PhD Opportunities

Possible research topics to be undertaken in the Aerospace Sciences Division are given below. If you are interested in any of these projects, you should email the prospective academic.

Alternatively, you are welcome to identify a different project topic within any relevant research area by emailing your project proposal to any of the Staff of the Aerospace Sciences Division using the Our Staff link on the left panel.

The current call for scholarship applications will close on January 31st 2021.

Propeller aerodynamics

Dr Richard Green and Prof George Barakos

Description

Propellers are an important class of propulsion system due to their extremely high efficiency at low flight speed. Impressive understanding of propeller aerodynamics was gained leading up to the 1940s, but propellers have been overlooked for decades with research concentrating upon propulsion systems for higher speed flight. Interest is being revived with a drive towards so-called greener aviation and possibilities afforded by distributed propulsion systems due to electrification. Recent research at Glasgow University into propeller aerodynamics has investigated the inflow to a propeller, and it has been revealed that the flow field has far more interesting features than have been previously supposed. This project is to extend this work by looking at the flow leading into propellers due to installation effects, for example due to the position of a wing or fuselage nearby. The project will use experimental methods in a wind tunnel.


Low-order modelling of unsteady, nonlinear fluid dynamics using “Scientifically-Based” machine learning

Dr Kiran Ramesh

Description

In the last 2 decades, the field of fluids engineering has seen an explosion of research interest in new ideas and concepts, such as: wind/tidal energy conversion devices, unmanned air vehicles (UAVs), high-altitude long endurance (HALE) aircraft, electric vertical take-off and landing (eVTOL) vehicles, and blended-wing-body (BWB) aircraft using distributed electric propulsion. All these research themes are aligned with the overarching 21st century goal of generating clean energy and reducing emissions of pollutants and greenhouse gases due to transport. Hence "optimal designs" are desired, but suitable design methodologies for these problems aren't yet available. This is primarily because all of these problems in some manner involve unsteady and nonlinear fluid flow, for which analytical solutions which are usually the basis of design methodologies aren't available.

 

In the project, we propose to augment physics-based equations and models with machine-learnable structures in the field of unsteady, nonlinear fluid dynamics. This "scientifically-based" learning approach will enable discovery of previously unknown governing terms/equations, accurate extrapolation beyond the training data, and acceleration of model simulation.

 

Using the recently-discovered topology and dynamics of dynamic-stall-type unsteady flows[1], we propose to split the full, complex topology into constituent unsteady flows which may be represented by Ordinary Differential Equations. The ODE system will be augmented with neural-network structures that account for nonlinear interactions absent from the physics-model. The resulting system will be trained with high-fidelity computational fluid dynamics (CFD) data generated using the open-source software package OpenFOAM. We aim to uncover new terms in the system of equations describing the flow that are absent in the scientific model based on ideal flow conditions. We expect that the trained solver will be able to make real-time, accurate predictions of flows that are loosely based on the dynamic-stall-topology (containing boundary-layer separation and leading-edge vortex formation), even when the conditions are far from ideal.

 

Pre-requisites: Interest (and preferably experience) in theoretical and numerical methods in fluid dynamics, interest in AI and machine learning .

 

[1] Widmann, A., and Tropea, C. "Parameters influencing vortex growth and detachment on unsteady aerodynamic profiles." Journal of Fluid Mechanics 773 (2015): 432-459.


Numerical and Experimental Study of Propeller Aeroelasticity – NESPA [FUNDED]

Prof George Barakos

Description

Two PhD studentships are available in the area of propeller aeroelasticity. The studentships are funded by GE-DOWTY and the University of Glasgow and build on a long-standing relationship with the sponsor on propeller research. The studentships are part of the NESPA project aiming to deliver a propeller blade that will exhibit stall flutter behaviour during wind tunnel tests. The two students will follow from the work documented in an existing PhD thesis on propeller flutter and will also collaborate with post-doctoral researchers working on the same topic. The tools (both numerical and experimental) are based on the flagship rotor project MENtOR of the UK, that delivers both CFD tools and a rotor rig for wind tunnel tests.

Stall flutter is seen as a potential hurdle in the progress of turbo-prop designs and may threaten the delivery of new, faster, quieter, and efficient blades. The same problem manifests itself on tilt-rotor blades at high speed, multi-rotor hybrid/electric aircraft and may limit the potential use of RPM-regulated rotor systems. Research in this area is expected to have strong impact in future aircraft designs.

The first student is to focus on the blade design, its modelling and simulation using state-of-the-art methods for propeller aerodynamics developed at Glasgow. The idea is to establish the stall flutter envelope and identify the conditions that can be used to demonstrate stall flutter during propeller operation. This area of research has been identified as early as the days of the spitfire aircraft but without accurate tools useable in stalled flow it is difficult to address.

The second student will focus on delivering state-of-the-art data showing the physics of the solid/fluid interaction during flutter, measured at resolution required for validation of modern aeroelastic simulation methods. To date, there is no such data set available. The use of a large-scale rotor test rig and the availability of several flow diagnostic methods will allow the student to characterize the stalled flow on the blades in great detail and resolved in time. At the same time, measuring the dynamic response of the blade and the evolving blade shape during flutter will allow the student to deliver a unique insight in a complex phenomenon.

The students will benefit from the existing research and environment at Glasgow, its computer and wind tunnel facilities, its rich rotorcraft research community, the close collaboration with industry, and the overall exposure to the UK Vertical Lift Network that Glasgow is leading.

Enthusiasm about aerospace engineering, professionalism and commitment to research are essential. Experience with CFD methods, aeroelasticity, modelling and simulation, computer programming, wind tunnel experimentation, data analysis and fluid mechanic are desirable.

The closing data for applications is February 11, 2021 though students may start between January and June 2021.

Interested students are encouraged to apply here, and further questions can be directed to Prof. George Barakos (george.barakos@glasgow.ac.uk) on the modelling and simulation studentship, and Dr Richard Green (richard.green@glasgow.ac.uk) on the experimental studentship.

 


In-orbit assembly: Robust autonomous methods for controlling robot manipulators in space

Dr Kevin Worrall and Dr Gerardo Aragon Camarasa

Description

With the current push towards space for both private and government organizations, and the recent increase on initiatives to the industrialization of space, there will be an important need for humans to be supported by robotic systems. Understanding and mastering the unique properties that will intervene in the robot behaviour is essential to offer a fully autonomous robotic system which will be expected to work with no human intervention while being robust, accurate and responsive.

The work will consider the different advantages of both traditional and AI-based control methodologies to support the development of a vision-based control system that is able to control a robot manipulator within the space environment during in-orbit assembly tasks. The expected outcome of this work will be a simulation environment of a suitable setup and a practical real-life implementation.

This project will engage with recent research studies on the field on autonomous robotics, building in-orbit structures, satellite assembly and support studies on manufacturing in space. This project can also engage with users beyond space, with advanced manufacturing research being a potential area to explore.

Background in either control engineering mechatronics, computing science, and/or space engineering is highly recommended. In order to be eligible to apply for the School of Engineering Scholarship, an excellent CV is required.

Funding

Currently unfunded. Please consult the Postgraduate Research section for information on applying for support. 


Novel Electric Advanced Thrusters for space propulsion

Dr Enric Grustan-Gutiérrez

Description

Space and Exploration Technology Group (SET) is looking for enthusiastic candidates to pursue a PhD developing advanced Electric Thrusters for spacecrafts.

The rapid increase in market share for SmallSats and the future deployment of large constellations have increased demand for propulsive systems capable of providing thrust at both high propellant efficiency (SI) and total efficiency at low power operating conditions. The current state-of-art electric propulsion adopted for medium to large-sized space platforms can provide impressive system performance. However, this performance is always associated with both significant volume, high costs and limited capabilities of being scaled down in size, while retaining system performance.

Electrospray is an excellent method to atomise dielectric liquids into a beam of charged particles that can be accelerated up to tens of Km/s. A single electrospray source delivers thrust at high SI and efficiency at naturally low power and thrust levels -in the micro-Newton and milli-Watt range. Unfortunately, these levels are insufficient for the current needs of the SmallSats market; ideally, the thrust output of a propulsive system should increase at least a hundred-fold for a total power consumption of few Watts. Therefore, the natural solution to increase the overall thrust is multiplying the number of electrospray sources operating at the same time. The small cross-section of a single source and the use of microfabrication techniques allow this feat without increasing the volume of the whole system. 

This project strives to design and develop a fully integrated and scalable Electrospray Propulsion System using the microfabrication capabilities of the state-of-the-art facilities of the James Watt Nanofabrication Centre and the testing resources of the department. The JWNC is a 1400 m2 cleanroom at the University of Glasgow which houses over £35M of fabrication and metrology equipment. It is one of the leading centres of research and international collaboration in micro and nanofabrication technologies undertaking fundamental, applied and commercial research, and small industrial prototyping and production runs.

Established in 1451, the University of Glasgow has been home to aerospace research for over 80 years, and today our researchers are tackling the multidisciplinary challenges faced by the aerospace industry in the 21st century. In the latest "Complete University Guide", the School of Engineering was ranked 2nd for Aeronautical and Manufacturing Engineering.

The ideal PhD candidate has a degree in either aerospace, nanoscale or electronic engineering, microelectronics or applied physics and an excellent track record. 

Funding and application

Scholarships are available for UK citizens and exceptional EU candidates, for details, please get in touch using the details below.

For funding opportunities and the application process, please consult: https://www.gla.ac.uk/schools/engineering/phdopportunities/ 

Contact

For an informal discussion or further information on this project, please contact: enric.grustangutierrez@glasgow.ac.uk


In-orbit fabrication of large space structures using novel manufacturing technologies

 

Professor Colin McInnes

 

This exciting new project will investigate a range of strategies for in-orbit fabrication, include the use of directed energy deposition methods. Such methods will enable the manufacture of metal-based structures in orbit from powder feedstock. However, there are a range of challenges to be overcome, including handling of feedstock in orbit and thermal control. The project will address such issues through design, simulation and laboratory-based experiment. Novel structures which could be fabricated using these methods will be considred and applications sought, including antennae and optical reflectors.

As a new development, the use of feedstock from a metal-rich meteorite sample will be investigated to demonstrate the fabrication of thin reflective films from asteroid material. It is expected that samples will be fabricated and their optical and mechanical properties characterized to understand the scaling of such methods towards large-scale in-orbit fabrication. 

The project will involved modelling and simulation and laboratory-based technology development and demonstration. The successful candidate will join a team of researchers working on a range of emerging space technologies, as part of the Space and Exploration Technology Group (SET):

The group’s facilities include the Integrated Space and Exploration Technologies Laboratory (I-SET) which hosts an air bearing and Helmholtz cage, vacuum chamber, clean room area and 3D printing facilities.


Investigation of axisymmetric turbulent boundary layers using direct numerical simulation

Dr Angela Busse

Description

Many empirical relationships used in the context of wall-bounded turbulent flows have been obtained under the assumption that the wall is flat, e.g. by approximating the geometry as a flat plate or channel flow. However, turbulent boundary layers that develop over surfaces that are strongly curved can exhibit a different behaviour. An example is the case of the turbulent boundary that develops along the axial direction of a circular cylinder with a high length to diameter ratio. This type of configuration occurs for example in the context of towed array sonars which are used to conduct geological surveys of the seabed.

Unlike the flat-plate turbulent boundary layer, which has been studied widely, there is currently only limited experimental and numerical data available on axisymmetric boundary layers. In this project, direct numerical simulations (DNS) will be used to investigate axisymmetric turbulent boundary layers. In the first phase, the smooth wall case will be investigated. In the second phase, effect of surfaces roughness, e.g. due to marine biofouling, will be included.


Vortex dynamics

Dr Richard Green and Dr Hossein Zare-Behtash

Description

Propellers are an important class of propulsion system due to their extremely high efficiency at low flight speed. Impressive understanding of propeller aerodynamics was gained leading up to the 1940s, but propellers have been overlooked for decades with research concentrating upon propulsion systems for higher speed flight. Interest is being revived with a drive towards so-called greener aviation and possibilities afforded by distributed propulsion systems due to electrification. Recent research at Glasgow University into propeller aerodynamics has investigated the inflow to a propeller, and it has been revealed that the flow field has far more interesting features than have been previously supposed. This project is to extend this work by looking at the flow leading into propellers due to installation effects, for example due to the position of a wing or fuselage nearby. The project will use experimental methods in a wind tunnel.


Flow over bodies with excrescencies due to growth of biological matter

Dr Richard Green and Dr Angela Busse

Description

Shipping, marine structures, and tidal turbines all suffer significant performance degradation due to growth of biological agents. These include algae and plant growth and encrustation by animals such as barnacles. Research work in this field has been conducted at Glasgow using theoretical, computational and experimental approaches, and this research project is to build upon this. Candidate projects include the effect of barnacle encrustation on hydrofoil surfaces for use with tidal turbines, and specifically what is the loss of potential power production due to this? There is limited understanding of the unsteady flow field in the presence of isolated barnacles or clusters of them, and this aspect is expected to be the major thrust of this research effort. Both supervisors have extensive experience in computational and experimental work in this field, and the PhD candidate will be expected to develop computational and experimental methods. Contact either Dr. Angela Busse or Dr Richard Green if you are interested in conducting a research project in this field.


Unsteady flow of jets and wakes

Dr Richard Green and Dr Angela Busse

Description

Fluid dynamic jets and wakes are rich in phenomena of fundamental significance that are fascinating to observe but are a challenge to predict, measure and understand. As such jets and wake flows have formed the basis of many investigations in fluid dynamics that are relevant to flows in nature, for aircraft and other vehicles, civil engineering, meteorology among other fields. Of particular importance are jet and wake flows that break down into powerful vortex structures as a consequence of the development of fluid dynamic instabilities. Experience at Glasgow in this research in this area includes development of rotor wakes, jet configurations and bluff bodies for the study of both fundamental fluid dynamics and applied aerodynamics. The project supervisors have extensive research experience in this field, and use computational, theoretical and experimental approaches. Contact either Dr. Angela Busse or Dr Richard Green if you are interested in conducting a research project in this field.


Development of theoretical methods for unsteady flows and vortex dynamics

Dr Kiran Ramesh

Description

In the last 2 decades, the field of fluids engineering has seen an explosion of research interest in new ideas and concepts, such as: wind/tidal energy conversion devices, unmanned air vehicles (UAVs), high-altitude long endurance (HALE) aircraft, electric vertical take-off and landing (eVTOL) vehicles, and blended-wing-body (BWB) aircraft using distributed electric propulsion. All these research themes are aligned with the overarching 21st century goal of generating clean energy and reducing emissions of pollutants and greenhouse gases due to transport. Hence "optimal designs" are desired, but suitable design methodologies for these problems aren't yet available. This is primarily because all of these problems in some manner involve unsteady and nonlinear fluid flow, for which analytical solutions which are usually the basis of design methodologies aren't available.

 

This project will use analytical and mathematical methods to develop new ways of modelling unsteady flows. In past research, for example, our group has introduced the Leading Edge Suction Parameter (LESP), calculated as a measure of theoretical suction/velocity at the aerofoil leading edge [1]. Using the LESP criterion to regulate start/stop of LEV shedding, we further developed a discrete- vortex method (DVM) which permits intermittent vortex shedding from the aerofoil's leading-edge [1].

 

The project aims are to develop methods to predict and model (i) general flow separation and (ii) transition to turbulence. These will be derived from the unsteady boundary-layer and Navier-Stokes equations, using concepts such as perturbation methods, matched asymptotic expansions and self-similarity.

 

Pre-requisites: Interest (and preferably experience) in theoretical and analytical methods in fluid dynamics. 

 

[1] K. Ramesh, A. Gopalarathnam, K. Granlund, M. V. Ol and J. R. Edwards, "Discrete-vortex method with novel shedding criterion for unsteady airfoil flows with intermittent leading-edge vortex shedding," Journal of Fluid Mechanics, vol. 751, pp. 500-538, 2014.


Real-time simulation of unsteady, separated flows about arbitrary geometries

Dr Kiran Ramesh

Description

The advent of fast computers and the need for more realistic flight simulations put new demands on computational aerodynamics for methods that have a good level of fidelity and can run efficiently for large-scale problems.

 

In this project, a 3D discrete-vortex model will be developed for simulating flow around arbitrary, deforming geometries. The PhD student in this project will work alongside other researchers in theoretical and numerical fluid dynamics. The code development will be based on the existing code platform UNSflow[1].

 

The development of UNSflow is inspired by XFOIL, a low-order aerodynamic solver for steady flows. Originally developed at the Massachusetts Institute of Technology in the 1980s, it remains widely used for aerofoil analysis and design even 3 decades later. Its distinguishing features are a simple graphical interface to interact with the solver, an intuitive physical description of the solution (transition location, separation location, lift and drag coefficients, flow visualisation, etc.) and the options to carry out parametric studies. Recognising that much of current aerospace research involves unsteady aerodynamics, UNSflow intends to provide similar functionality to the aerospace community for studies and applications involving unsteady flow phenomena.

 

GPU computing will be used to speed up the discrete-vortex simulation to make it real-time. The potential use of this code in AR and VR applications will be investigated (with a potential partnership with Rolls Royce).

 

Pre-requisites: Interest (and preferably experience) in numerical methods in fluid dynamics. 

 

[1] https://github.com/KiranUofG/UnsteadyFlowSolvers.jl

 


Flow control in unsteady flows, and use in active flight control

Dr Kiran Ramesh

Description

The concept of flow control has existed since Prandtl, who introduced the idea alongside boundary- layer (BL) theory. However, only few realizations of flow control are seen in practice, and they primarily involve triggering early transition to turbulence in order to prevent laminar separation. Progress in flow control techniques has frequently been achieved by experimentation, experience and luck, and for this reason Active Flow Control has been (somewhat mockingly) referred to as an art rather than science in the literature

 

The goal of this project is to move away from the “trial-and-error” or “brute-force” approaches to investigating flow control mechanisms, and to instead develop a “design process / methodology” for the same.

 

In past research, our research group has introduced new low-order methods of simulating and studying unsteady flows [1]. These methods are unique in that they are based on phenomenological augmentation of inviscid aerodynamic theory, using numerical computations to account for departures from the assumptions made in theory (such as finite viscosity and flow separation). These models will be used to enable flow control studies in this project owing to their low time and cost consumption, their ability to be easily modified/augmented for multidisciplinary problems and also since they provide additional insight into the most important flow phenomena associated with the problem.

 

Control strategies for laminar flow reversal and separation through suitable changes to the boundary conditions of the BL equations will be investigated. The study is fundamental in nature and intended to develop a new design-based perspective of flow control. Extensions to transitional and turbulent boundary layers will also be considered.

 

Three representative problems which all involve flow separation will be used to test and illustrate the approach and methods developed through this project (at low Reynolds numbers): (i) 2D dynamic stall, (ii) Swept wing at high angle-of-attack, (iii) Finite wing encountering a gust.

 

Pre-requisites: Interest (and preferably experience) in analytical and numerical methods in fluid dynamics. 

 

[1] K. Ramesh, A. Gopalarathnam, K. Granlund, M. V. Ol and J. R. Edwards, "Discrete-vortex method with novel shedding criterion for unsteady airfoil flows with intermittent leading-edge vortex shedding," Journal of Fluid Mechanics, vol. 751, pp. 500-538, 2014.


High Performance Bio-Inspired Topologically Optimised and Smart Composite Structures

Dr Mohammad Fotouhi

Description

Polymer matrix composites usage is growing rapidly due to their superior strength, stiffness, lightness and low susceptibility to fatigue and corrosion. There is rapid expansion of composite use in aerospace and other applications, such as wind turbine blades, sporting goods and civil engineering. Recent examples include large civil aircraft, such as the Boeing 787 and the Airbus A350, high performance cars, such as the McLaren 650S, and civil infrastructure, such as the Mount Pleasant bridge on the M6 motorway. Despite this progress, composite structures will often fail through poor design, where stress concentrations appear around sharp changes in topology e.g. edges, holes, corners, or due to concentrated loads such as impact. In addition, the damage in composite materials is hidden and failure is without any warning and mainly catastrophic. Therefore, designers are forced to apply conservative design approaches which do not fully exploit the properties. For example, maximum allowable design strains can be as low as 0.1% for carbon fibre composites, despite maximum failure strains of up to 2%.

This project intends to explore bio-inspired examples of stress distribution in living organisms and to utilise some of those methodologies in the design of composites structures. These designs can be mimicked due to advances in modelling, characterisation and manufacturing of composites. The project’s vision is to develop a new generation of high-performance and smart composite structures based on nature’s generative design principles to overcome the aforementioned limitations. These bio-inspired algorithm-based composites will improve both safety and design strain limits at the same time, shifting the traditional dilemma between performance and safety. A step change in the design and performance will be achieved compared to current materials, resulting in simple and cheap approaches for optimal design and health monitoring. The outcomes of this project will enable full exploitation of the weight saving benefit in composite structures by overcoming the limitations of traditional conservative designs and avoiding expensive inspections. Such materials will provide greater reliability and safety, together with reduced design and maintenance requirements, and longer service life.

The key research questions: 1. How to produce bio-inspired topologically optimized and smart composite structures to overcome the limitations of current composite structures, i.e. over-engineering and catastrophic failure. 2. How to generate design tools for implementation of these high-performance bio-inspired topologically optimized and smart composite structures?

Established in 1451, the University of Glasgow has been a home to aerospace research for over 80 years, and today our researchers are tackling the multidisciplinary challenges faced by the aerospace industry in the 21st century. We have excellent modelling, simulation and ESA-ESTEC Testing facilities. 

The ideal PhD candidate has a degree in either aerospace, mechanical, materials, or a related area with an excellent research track record. 

Funding and application

For funding opportunities and the application process, please consult: https://www.gla.ac.uk/schools/engineering/phdopportunities/ 

Contact

For an informal discussion or further information on this project, please contact: mohammad.fotouhi@glasgow.ac.uk


A theoretical and experimental investigation of subscale flight testing

Dr. David Anderson

Description

Accurate subscale models have been used by aircraft designers since the earliest days of flight and continue to inform the design process of new aircraft today. The most common use of accurate models is in wind-tunnel testing, where the objective is to predict aircraft aerodynamic loading and interactions for a range of flight conditions. However, there are limitations to the range of experiments that can be conducted within a wind tunnel, particularly when measuring loads under dynamic vehicle conditions. Unfortunately, understanding such edge cases is critical when developing new high-bandwidth flight controllers, to ensure aircraft safety, efficient operation etc., with problems often only discovered during the final flight-testing programme, leading to very costly delays. Consequently, there is a desire (and significant financial benefit) to be able to identify any stability, control or performance issues earlier in the design process.

This PhD research project will investigate the usefulness of data obtained from conducting subscale flight tests with dynamically scaled aircraft within the context of aircraft design. Overcoming the issues associated with Reynolds number scaling – a significant problem for wind-tunnel experiments will be the primary objective. Specifically, machine learning techniques will be used to extrapolate data collected during subscale flight tests to help validate mathematical models of the full-scale aircraft. This will be accomplished by developing an accurate mathematical simulation that can be configured for both full-scale aircraft and models of differing dynamic scale factor. Model validation at the subscale end will be achieved by fabricating several dynamically scaled aircraft with a common sensor suite and conducting a flight test program for each. To ensure that flight test data for the full-scale aircraft will also be available, the vehicle chosen for this study will be Cranfield Universities new flying laboratory aircraft, the SAAB 340B.

 


Learned Vision Based Obstacle Avoidance for μUAV

Dr Kevin Worrall

Description

 

The capabilities of UAVs and μUAVs are expanding each year. There are autonomous UAVs that can fly in open and complex environments and UAV’s that can delivery supplies and operate as remote sensors.

One reason for this is the increase in processing power, and the size reduction, of microelectronic devices and sensors. With the new capabilities of the microelectronic devices available there is now a drive to implement onboard vision based navigation and obstacle avoidance for UAVs and μUAVs. This method of navigation/obstacle avoidance could further improve the capabilities of the systems and provide a means to increase the range of applications that can be carried out by the UAVs.

This project is to consider the use of an onboard vision system for obstacle avoidance. The aim of which is to allow a UAV to fly freely around a complex unpredictable environment. It is proposed that to achieve this the system is required to learn what obstacles are and then react to them.

Using machine learning, it is envisioned that a suitable algorithm can learn what obstacles are and, using this knowledge, provide a means in which to successfully implement an obstacle avoidance routine on board the uUAV.

This work will involve:

  • Implementation and testing of machine learning algorithms
  • Hardware implementation and testing of algorithms
  • Comparison of algorithms for different scenarios

The ideal candidate will have a strong background in software and control with experience of hardware and an excellent track record, preferably including evidence of outstanding research, such as previous awards and/or publications.


Effects on roughness shape and distribution on performance of aero- and hydrofoils

Dr Angela Busse and Dr Marco Vezza

Description


Due to their exposure to harsh environments, wind and marine turbines suffer from pitting and fouling during their service resulting in the formation roughness on the turbine blades. Once the surface roughness exceeds the hydraulically smooth limit, it will affect the boundary layer over the surface and result in altered performance of the aero- or hydrofoil, e.g. a reduced lift and an increased drag coefficient. 

However, roughness comes in many different forms, e.g. surface fouling will result in a different topography compared to surface pitting or gouging. In addition, the roughness topography of the turbine blade will evolve as the processes causing the formation of roughness progress in time. Finally, the change in the performance will strongly depend on what part of the blade is most strongly affected by roughness built-up, i.e. the spatial distribution of the roughness.

The aim of this project is to systematically investigate the effect of roughness topography and distribution on the performance of aero- or hydrofoils using RANS and large-eddy simulations. In the first part of the project, the numerical approach will be validated against existing experimental data. In the next stage of the project, numerical simulations will be performed for a wide range of realistic roughness types and for representative aero- and hydrofoil shapes. In the final part of the project, the influence of roughness shape and distribution on the flow over moving aerofoils, e.g. undergoing a pitching motion, will be investigated. The aim is to develop a comprehensive classification of roughness effects on aerofoils, which will help in developing cost-effective maintenance strategies for off-shore wind turbines.


Improvement of wheeled vehicle safety and performance using inverse simulation

Dr Douglas Thomson and Euan McGookin

Description

Wheeled vehicles are used for many different transportation applications e.g. road transportation, off-road travel, mobility.  Each scenario has its own requirements in terms of performance and the specification of the vehicle.  However, all have safety as a main concern and requirement for the operation of these types of vehicle.  In particular road safety has become a focus for government bodies and the automotive industry in an attempt to reduce fatalities. One way of improving safety is through in-vehicle assistance where the driver is provided with assistive cues that direct their driving in a safe manner.  In addition, the operation of the vehicle on rough terrain can be enhanced through assistive control systems that compensate for variations in the ground profile. To implement such assistive technologies there needs to be knowledge of how desired driving trajectories can manifest themselves as inputs to the vehicle.  A novel technique that can generate such a relationship from the dynamics of the vehicle is Inverse Simulation. 

Inverse Simulation is a method by which the control inputs necessary for a given system to respond in a defined manner can be calculated.  The most common area where this method is applied is in the aerospace field where the pilot control inputs necessary for an aircraft to fly a specific manoeuvre can be calculated based on an inverse structuring of an appropriate mathematical model.  Recent work at the University of Glasgow has demonstrated that the mathematical model can be treated as a module of the Inverse Simulation algorithm allowing its use for various dynamic systems.  Inverse Simulation works by taking such a standard mathematical model and solving it in a conventional form over a discrete time step.  It is an iterative process where step changes in the various controls are applied until the predicted response matches the predefined response.   Its value can be as a predictive tool for design or optimisation, or it can be inherent in the basic control system design. 

For wheeled vehicle safety, Inverse Simulation could be used to define an optimum driving corridor that would provide safe and/or efficient utilisation of the vehicle.  This corridor would be a spatial/temporal path for the driver to follow.  The underlying Inverse Simulation would be based on a mathematical model of the vehicle and suspension system dynamics for an estimate of the current driving conditions ahead.  The driver would be instructed on the best way to improve their own driving skills and maximise the performance of the vehicle. 

The aim of this project will be to develop an appropriate mathematical model of wheeled vehicles for different applications (e.g. road driving, off-road and mobility) and apply the techniques of Inverse Simulation to them. The Inverse Simulation will then be used in a number of case studies to demonstrate the capabilities of this method in the design and analysis of systems for wheeled vehicles.  These applications will include driver assistance and automatic control of the vehicles being considered.


Aerodynamics and aeroelasticity of a very flexible kite wing

Prof George Barakos and Dr Rene Steijl

Description

Very flexible wings are currently used for recreational flight (paragliding, parachuting etc.) but have large potential to be used as wind energy harvesters. Tethered flexible wings flying in a loop can deliver enough mechanical power on the ground to drive electric generators.

Within aerodynamics and aeroelasticity, there is very little knowledge on the behaviour of very flexible wings and this knowledge gap is to be addressed with the proposed project via state-of-the-art simulation. The HMB set of tools of Glasgow University is to be used for this purpose and the research will focus on the distribution of the aerodynamic loads on the wing during a wind gust or a rapid manoeuvre where the wing shape changes quickly and the kite efficiency is reduced.

The project requires coupled aerodynamic and structural dynamic calculations and falls within the area of low-speed aeroelasticity. In addition to the simulation data, existing experimental data for a rigid wing at low speed conditions will be used for comparisons.

The project objectives are:

  1. Demonstration of the HMB tool for aeroelastic computations for a very flexible kite
  2. Investigation of the flow field around the kite wing and study of the unsteady aerodynamics of a manoeuvring lifting body
  3. Study of the wing loads during rapid changes of the inflow angle combined with a simple model of the kit flight dynamics
  4. Aeroelastic investigation of the collapse and recovery of the wing shape during rapid inflow changes
  5. Extraction of guidelines for the design of flexible manoeuvring wings

The computations will be performed using local and remote high performance computing clusters and there is close collaboration with an innovative company specialising in the design of wind energy harvesters using flexible wings.

An ideal candidate for this project should have a first degree in Aerospace, Mechanical or Applied Mathematics degree. Knowledge of CFD, Aeroelasticity, computer programming and high performance computing are additional advantages. 


Investigation of novel hybrid wind turbine configurations

Dr Kiran Ramesh and Prof George Barakos

Description

Horizontal-axis wind turbine configurations, despite having higher efficiencies than their vertical-axis counterparts, are limited by the aerodynamic torque that they can withstand at high speeds. A novel strategy to improve on their performance would be to couple them with a vertical-axis turbine such that their drivetrains are integrated. Excess torque from the HAWT would then be transferred to the VAWT rotor, thus increasing the rated wind speed for power generation of the whole system. This concept also alleviates the self-starting problem typically encountered by VAWTs.  

In order to systematically investigate the benefits of this proposed hybrid system, a large parametric study encompassing the various HAWT and VAWT design variables will be performed in this project. The interactions between wakes generated by the two rotors are also of academic interest, and will be explored in detail.  

Preliminary studies and the initial sweep of the parameter space will be performed using the in-house low-order UNSflow solver which uses the vortex-blob method to represent the free wake and shed vorticity, and the viscous-inviscid interaction approach to resolve the aerodynamics boundary layers.

High-fidelity studies and state-of-the-art simulations will be performed using the in-house HMB solver on local and remote high performance computing clusters. 


Optimising active flow control on swept wings using sweeping jet actuators

Dr Rene Steijl and Prof George Barakos

Description

In the area of active flow control for aircraft applications, significant progress has been made in controlling the flow at low to moderate angles of attack at which large-scale flow separation does not occur. Key challenges remain at higher angles of attack, in particular when amount of airflow through the devices needs to be limited for practical reasons. A further complicating factor is that for practical applications such as unmanned aircraft and tail planes of commercial airliners, a large sweep angle is typically used, creating cross-flow instabilities in the boundary layers as well as more complex flow separation patterns as compared to a wing with small sweep angle. 

In this project, the emphasis is on a new type of active-flow control approach using 'sweeping jets'. These are actuators with a relatively small mass flow rate, designed to have a time-periodic angle of the jet emanating from the device. This 'sweeping' motion of the jet transfers momentum to the boundary layer and in a number of experiments this approach has proved effective in delaying stall. At present, the flow physics in the 'sweeping jet' devices is not yet fully understood. 

The proposed project aims to provide a systematic, detailed analysis of the flow field within the actuators, as well as the interaction with the main flow. Of particular interest is a reduction in the required mass flow rate, to be achieved by increasing the jet velocity to high transonic or even supersonic conditions.

Based on the increased understanding of these flows from the detailed analysis, a second step would then be an optimization process using advanced CFD techniques including an adjoint method to create optimized designs for these actuators.

One target applications of this work would be tail planes of airliners, where the flow separation delay to higher angles of attack would enable the use of smaller tail planes with a reduction in aerodynamic drag in cruise flight. A second application would be the stall delay of the highly swept wing of unmanned combat aircraft.

In summary the objectives of the proposed project are to:

1. Identify and understand the main physical processes and parameters in the design of ‘sweeping jet' actuators with supersonic outflow.


Effects on roughness shape and distribution on performance of aerofoils

Dr. Angela Busse and Dr. Marco Vezza

Description

Due to their exposure to harsh environments, wind and marine turbines suffer from pitting and fouling during their service resulting in the formation roughness on the turbine blades. Once the surface roughness exceeds the hydraulically smooth limit, it will affect the boundary layer over the surface and result in altered performance of the aero- or hydrofoil, e.g. a reduced lift and an increased drag coefficient.

However, roughness comes in many different forms, e.g. surface fouling will result in a different topography compared to surface pitting or gouging. In addition, the roughness topography of the turbine blade will evolve as the process causing the formation of roughness progresses in time. Finally, the change in the performance will strongly depend on which part of the blade is most strongly affected by roughness built-up, i.e. the distribution of the roughness.

The aim of this project is to systematically investigate the effect of roughness topography and distribution on the performance of an aero- or hydrofoil using a RANS and large-eddy simulations. In the first part of the project, the numerical approach will be validated against existing experimental data. In the next stage of the project, numerical simulations will be performed for a wide range of realistic roughness types and for representative aero- and hydrofoil shapes. In the final part of the project, the influence of roughness shape and distribution on to flow over moving aerofoils, e.g. undergoing a pitching motion, will be investigated. The aim is to develop a comprehensive classification of roughness effects on aerofoils, which will help in developing cost-effective maintenance strategies for off-shore wind turbines.

 


Effect of turbulent flow structures and river-bed roughness on sediment transport

Dr. Angela Busse and Dr. Manousos Valyrakis

Description

Over 5 million people in the United Kingdom live in regions of elevated risk from extreme hydrologic events such as flooding and storm surges. The December 2015 flooding in North-West England has demonstrated once again the big impact these events have on society. The number of extreme hydrologic events is expected to further increase due to the combined effects of climate change and urbanisation. As weather phenomena intensify, so do the geomorphic processes that are primarily responsible for shaping the Earth’s surface. Such effects can be alleviated by improving the management of rivers and estuaries considering linkages between form and function of the water surface bodies. This however requires a better understanding of the mechanics of sediment transport, so that better numerical tools can be developed to predict these phenomena.
Recent developments have highlighted the role of highly fluctuating turbulent forces on the transport of sediment grains laying on the river bed surface. However, in many established models only a time-averaged representation of the turbulent flow field is considered, failing to take into account the highly intermittent small-scale fluctuations. In addition, the structure of the turbulent flow and the topography of the river bed have a strong influence on sediment transport.

In this project direct numerical simulations will be used to investigate the properties of the instantaneous near-wall turbulent fluctuations in riverbeds and their influence on sediment transport. The numerical results will be compared to experimental measurements and will improve our understanding: a) of flow over different types of bed roughness and b) of flows past flow obstructions of varying structural complexity (e.g. from solid cylinders to flexible-porous vegetation elements).


Development of novel chemical reaction models for hypersonic flows

Dr. Craig White and Dr. Rene Steijl

Description

Vibrational energy, electronic energy, and chemical reactions are an important physical feature of hypersonic flows. The extremely high temperatures found behind shock waves can provide enough energy to activate the vibrational and electronic modes, and allows endothermic reactions, such as dissociation of nitrogen and oxygen, to take place. The level of uncertainty in reaction rates at high temperatures is high because no reliable experimental data is available, but using accepted rates for the occurrence of these reactions is important from an engineering perspective, in order to predict the flow temperature and heat flux to the hypersonic body.

This entirely numerical project will make use of two in-house numerical codes, for both continuum and rarefied gas regimes. A parrticle method will be used for the rarefied conditions at higher altitudes and to inform new models to be implemented in the continuum solver. The continuum solver uses gas-kinetic schemes and is applicable to low levels of rarefaction. Coupling these solvers would be a novel research direction, but some work is first required to bring their physical models into closer alignment.

An anharmonic oscillator model for the vibrational energy states will be implemented in the particle solver for rarefied flows. Such an approach for the vibrational modes will have an influence on the implemented chemical reaction rates. This influence has not previously been documented and will need to be carefully examined. In the foreseen main part of the project, data from the rarefied code’s chemical reactions will be collated and used to propose and implement novel engineering level chemical reaction formulations in the continuum solver that will return results in agreement with the rarefied solver, allowing coupling of the two solvers through a flux and state based scheme.


An Experimental Investigation of Predictive Control Methods in Limiting Atmospheric Turbulence Response in Small and Micro UAVs

Dr. David Anderson and Dr. Richard Green

Description

All flight controllers must be designed to stabilise the aircraft against atmospheric turbulence. Effective controller design becomes more difficult for platforms whose aerodynamic surfaces are lightly loaded – a common situation for small Unmanned Aerial Systems (UAS) – and/or platforms with movable lifting surfaces such as the quadrotor, coaxial helicopter, ornithopter (flapping wing) etc. As the principal operational function of most UAS is airborne surveillance, accurate platform stabilisation is imperative for such systems. Therefore it is essential that accurate, validated models of the effects of atmospheric turbulence on the UAS be available to the flight control systems engineer during the design.

This research project is a continuation of a current investigation into the use of CFD-based simulation methods for predicting the response of small UAVs (quadrotors in this case) to atmospheric gusts typical of those found in an urban environment. Recent outputs from this research have shown that fusing the spatio-temporal turbulence field generated by the CFD models within the MAVERIC simulation environment generates qualitatively correct responses. However, conventional simulation methods alone cannot yield truly accurate models of the combined, interactional aerodynamic effects, for this we need to conduct wind tunnel experiments. Recently, the main wind tunnels in GU have undergone considerable modernisation which now allows experimental investigation of this type to be performed. However, to accurately quantify the response characteristics of small UAVs operating within low Reynolds number environments, an appropriate method for accurately generating statistically relevant turbulence within the wind tunnel will have to be determined and constructed. The turbulence field will be measured and tracked using PIV equipment and the UAV response measured using the balance. Assuming a safe operation mode can be determined, free-flight of the UAV will also be conducted inside the tunnel using motion capture cameras from the MAST lab.

The second phase of research will be to use the experimental data to populate models to assist in the design and analysis of nonlinear predictive controllers for optimal alleviation of atmospheric turbulence. The turbulence models will provide usable feedforward information to improve the efficacy of the predictive flight controllers. It is also hoped that the experiments will provide a database of sufficient scope to be able to ascertain if Kolmolgorov’s turbulence model of atmospheric turbulence is valid for small/micro UAV systems and if not, to propose a new turbulence model for these platforms.


Comparison of Biologically Inspired Propulsion and Navigation Systems for AUVs based on Fish and Aquatic Mammals

Dr. Euan McGookin

Description

The utilisation of Autonomous Underwater Vehicles (AUVs) has increased dramatically over the last decade and given rise to an associated multi-million pound industry. Initially this was due to the increase in oil exploration and extraction, which have come with the need to dive deeper in the world’s oceans in order to exploit reserves.  As a consequence AUVs have been deployed in deep water areas that are potentially hazardous to human divers. Their crucial functions within the underwater arena have made them invaluable for all underwater applications e.g. subsea survey, pipeline monitoring, pollution detection.

The operation of these vehicles has one main limiting factor: the lifespan of the on board power supply. With conventional AUV designs, propulsion is provided through the propeller based systems. This type of system draws large amounts of power from the battery during operation and the power drain is more severe during low speed manoeuvres where the motor is over used to maintain incremental motions. Consequently the power supply becomes depleted very quickly and the operational capability of the vehicle is greatly impaired. 

One approach to improve the propulsion efficiency of AUVs is to mimic the biological propulsion techniques exhibited by aquatic creatures i.e. tail based swimming. Instead of propeller systems, the AUV would have a biologically inspired or biomimetic propulsion system similar to a fish or aquatic mammal. Such a system would provide the required undulation to generate the unsteady vortex flow field along the body of the vehicle, which in turn produces the propulsive force for manoeuvring the vehicle. This approach has potential benefits over conventional methods including greater propulsive efficiency and increased manoeuvrability thus allowing increased mission duration and operational longevity. Also a biomimetic propulsion system would allow the AUV to operate within areas containing dense marine flora without becoming entangled. Further, the undulation of the tail will not disturb the water and river/sea bed as violently as a rotating propeller. This enables Biomimetic AUVs to operate without disturbing their swimming environment unnecessarily.

Obviously the physical characteristics of the AUV determine its functional capability and the environment it can operate within.  In this project the design of the biomimetic systems shall be based on horizontal fish tail undulation and vertical mammalian propulsion.  The design of both these types of system shall be the focus of this study, where the system will be developed and performance analysed through simulation.


Development of a Biomimetic Planetary Rover

Dr. Euan McGookin and Dr. Matteo Ceriotti

Description

Rovers have been used extensively for the exploration of planets, moons and other celestial bodies. Furthermore, recent scientific discoveries have sparked interest in exploring other planets’ moons such as Saturn’s Titan and Jupiter’s Europa. Naturally the diverse range of environmental conditions that could be encountered during exploration may not be suitable for existing rover systems.

Conventional rover designs have been wheel based for operations on firm ground surfaces and have proved successful in the exploration in this type of environment e.g. Mars. However, these types of rovers are not suitable for more fluidic environments where operation would be within dense gaseous or liquid atmospheres. In such scenarios the rover should have the capability to manoeuvre effectively within such atmospheric media and its design must reflect these operational requirements.

One suitable approach is to base the design of the rover on biological entities that live in similar environments on Earth e.g. fish and aquatic mammals. This would involve the development of a robotic system that was able to replicate the swimming gate of the particular biological species under consideration. In addition, an American university has recently proven that shape-morphing vehicles can be used as means to move both in the air and in the water, adapting to two fluids of very different density.  This approach could be used to morph the rover so that its swimming characteristics adapt to the operational environment.  

This proposed research project will involve the design and analysis of a biologically inspired or biomimetic rover concept, for example based on fish swimming, particularly anguilliform (eels) and sub-carangiform (salmonid). Such robotic systems should be highly robust and capable of adapting to a range of environmental conditions and properties, such as fluid composition, density, and temperature, as these not accurately known beforehand. This is typical of an unknown environment such as an unexplored area of a planet or moon.

Design considerations will include types of environments, materials, propulsion mechanisms, efficiencies and power requirements. These will be evaluated through simulations in MATLAB that have been validated against previous studies involving biomimetic autonomous underwater vehicles. Additional research will optimise the caudal motion to maximise its efficiency and minimise the reactions on the body. Proposed case-studies will involve the exploration of the atmosphere of Europa and Titan.


Fault Tolerant Guidance of Planetary Rovers Using Inverse Simulation

Dr. Euan McGookin and Dr. Douglas Thomson

Description

Rover systems have been increasingly used for planetary exploration over the last decade with particular success in the missions to Mars. Conventional operation of such planetary rovers has been based on remote guidance. However, future rovers are likely to have more autonomous functionality to improve mission effectiveness and minimise operational reliance on commands from Earth.

Although increasing the autonomy of the planetary rovers would improve operational capability, it does raise concerns about reliability. Therefore, the rover systems have to be designed to be fault free throughout their entire lifespan, which is impossible to achieve.  Alternatively they could be designed to be fault tolerant through health monitoring and appropriate fault recovery strategies. 

The fundamental process of health monitoring involves the detection and isolation of faults. For the autonomous operation of rovers the most important systems are the sensors and the actuators. If any of these crucial systems develop faults the rover would no longer operate correctly. To detect these faults the actual state of the rover is compared with an estimate provided by a suitable mathematical model. If the resulting residual exceeds specified thresholds then a fault is detected. Although this mechanism detects faults, it is difficult to ascertain which particular system is faulty due to the coupled dynamics of the rover. 

The process of automating the recovery of acceptable operation is susceptible to similar ambiguity. If the source of a fault cannot be isolated then it is difficult to determine an appropriate course of action that will compensate for the fault and ensure continued operation of the rover.

Existing methods used to overcome these hurdles require considerable amounts of historical data in order to generate relationships between observed symptoms and associated faults. Unfortunately in the case of planetary rovers the availability of such data is limited. Therefore, these classification methods for symptom/fault mapping would not be effective.

This project proposes that a novel alternative is to use Inverse Simulation to make autonomous rovers fault tolerant. Inverse Simulation uses mathematical models to determine the required inputs to generate predetermined output trajectories. In the context of fault tolerance, Inverse Simulation can be used to detect and isolate faults in sensors and actuators. Also, Inverse Simulation can be used in the recovery process once a fault has been detected. The utilisation of Inverse Simulation in both ways would allow the rover to continue to operate and thus complete its mission.


Improvement of Automotive Safety and Performance Using Inverse Simulation

Dr. Euan McGookin and Dr. Douglas Thomson

Description

Road safety has become a focus for government bodies and the automotive industry in an attempt to reduce fatalities. One way of improving road safety is through in-vehicle training or assistance where the driver is provided with assistive cues that direct their driving in a safe manner.  To implement such assistive technologies there needs to be knowledge of how desired driving trajectories can manifest themselves as inputs to the car.  A novel technique that can generate such a relationship from the dynamics of the vehicle is Inverse Simulation

Inverse Simulation is a method by which the control inputs necessary for a given system to respond in a defined manner can be calculated.  The most common area where this method is applied is in the aerospace field where the pilot control inputs necessary for an aircraft to fly a specific manoeuvre can be calculated based on an inverse structuring of an appropriate mathematical model.  Recent work at the University of Glasgow has demonstrated that the mathematical model can be treated as a module of the Inverse Simulation algorithm allowing its use for various dynamic systems.  Inverse Simulation works by taking such a standard mathematical model and solving it in a conventional form over a discrete time step.  It is an iterative process where step changes in the various controls are applied until the predicted response matches the predefined response.   Its value can be as a predictive tool for design or optimisation, or it can be inherent in the basic control system design. 

For road safety, Inverse Simulation could be used to define an optimum driving corridor that would provide safe and/or efficient utilisation of the vehicle.  This corridor would be a spatial/temporal path for the driver to follow.  The underlying Inverse Simulation would be based on a mathematical model of the vehicle and suspension system dynamics for an estimate of the current road conditions ahead.  The driver would be instructed on the best way to improve their own driving skills and maximise the performance of the car.

The aim of this project will be to develop an appropriate mathematical model of a road vehicle and apply the techniques of Inverse Simulation to it.  The Inverse Simulation will then be used in a number of case studies to demonstrate the capabilities of this method in the design and analysis of systems for road vehicles.  These will include driver assistance systems.


Ice-prediction simulation method for rotary wings

Prof. George N. Barakos and Dr. Rene Steijl

Description

The formation of ice on rotary wings (helicopter, wind turbine, propeller blades) is a complex problem that has so far been addressed by a very small number of researchers. Taking helicopters as an example, all-weather operation is necessary and icing on the blades can reduce their usefulness for performing vital operations of search and rescue. Much the same way, the installation of wind turbines off-shore, on floating platforms leads to the need for ice protection.  Ice protection is a much wider topic that anti-icing with the later including only the use of systems designed to remove ice once formed via electric hearing or via pneumatic boots near the leading edge of the wings.

The project takes a different approach to this problem and aims to develop design features on the blades that can reduce the formation of ice using passive designs that limit the amount of water in the proximity of the blade surface.

The first step (i) of the project is the development of an icing method capable to resolve complex icing cases within the Helicopter Multi-Block 3 solver of Glasgow. The method development in itself has 3 steps. The first step (i.1) is the addition of water vapour model that is based on transport equations. The second step (i.2) is a thermodynamic model of water condensation. This is combined with a water impact model that will deliver the exact amount droplets impacting a blade at every instance in time during flight. The last step (i.3) is a mesh deformation method that allows complex shapes to be accounted for. This last method is built on adaptive, immersed boundary algorithms that already exist in the flow solver but are only used for improving the prediction of flows. Making the ice prediction method available will provide a tool to engineers that can be used at design stage alongside the blade shape optimisation method. The second step (ii) is the exploitation of the method for computations at icing conditions using an advanced blade planform as the starting point. The ultimate goal is to improve the icing characteristics of the blade without severe penalties in the blade performance. The exercise will be repeated for a wind turbine blade of a large (10MW) machine.


Numerical analysis of advanced hybrid propulsion systems for hypersonic flight

Dr. Ian Taylor

Description

The retirement of the Space Shuttle, now over 5 years ago, has focussed attention on the technological hurdles that must be overcome to sustain future access to space. Major economies must be achieved, and the key is the ability to achieve single-stage to orbit (SSTO) with a re-usable launch vehicle. The realisation of SSTO relies heavily on the development of appropriate advanced propulsion systems. Indeed, the Shuttle failed to live up to economic expectations largely because of the incompatibility of its propulsion system with its intended mode of operation. The outstanding technological problems are huge: SSTO engines need to operate efficiently over the whole flight envelope, from take-off to hypersonic speeds, from continuum-gas conditions near the surface to the rarefied gas conditions at the edge of space.

Recent research activity by Dr Ian Taylor on propulsion systems has been focussed on scramjet engines, firstly using high resolution CFD to model the detailed shock structures at inlet and how they influence combustion, and secondly developing low fidelity, modular engine models to optimise engine performance and configuration. This proposal aims to build on this research by investigating hybrid engines that incorporate various engine architectures each optimised for different aspects of the flight envelope.

Hybrid engines are considered to be the most efficient approach for SSTO propulsion systems, with “conventional” gas turbines used for the low-speed and altitude flight, ramjet/scramjets at high speeds and altitudes, and rockets to extend the flight beyond the atmosphere. The research proposed will undertake a detailed numerical (CFD) investigation of the intake and engine-airframe configuration, assessing the effect on combustion at high speeds and on achieving stable engine operation. There will be a particular emphasis on understanding the transitions between the various engine operation modes, as any associated unsteady effects could strongly affect efficient engine operation. Also, the low fidelity model will be enhanced, with new models of the hybrid engine architecture and extended trajectory analysis to allow optimisation the flight envelope, thus identifying the ideal transition point between engine configurations. In both cases, open-source software, already available to Dr Taylor, will be used to undertake the numerical investigations. The deliverables of the research will be enhanced, state-of-the-art suite of numerical models for advance propulsion systems. Additionally, it will deliver a greater understanding of the physical phenomena associated with these systems to enable future solutions to be developed that bring SSTO closer to reality.

 


Aerodynamics of transport vehicles

Prof. Konstantinos Kontis and Dr. Angela Busse

Description

This project will investigate, both experimentally and numerically, the aerodynamics of road vehicles and rails. Particular focus will be on resolving instantaneous flow field around the chassis and the under-floor flow. This is a challenging project as state-of-the-art modern experimental techniques like high-speed stereo PIV, volumetric PIV, high-speed Background Oriented Schlieren (BOS), Pressure Sensitive Paint (PSP) measurements will be employed so that three-dimensional information of the flow could be obtained. Computational Fluid Dynamics (CFD) will also be used to predict the under-floor flow field as well as for validating the experimental data.

The importance of this project is that currently our understanding on vehicles and train aerodynamics is still remained at the level of time-averaged flow field. Only limited studies have been conducted to resolve the instantaneous flow field around vehicles and rails. The information obtained from the instantaneous flow field is particular important for understanding the flow physics of under-floor flow of road vehicles. It is generally believed that the interactions between the rolling wheels and the chassis create significant amount of noise and drag. The interactions also affect the handling quality of a vehicle.

In addition, the unsteady flow generated by the rolling wheels of a vehicle also affects the stability of vehicles which are riding near a heavy vehicle. Understanding the under-floor flow of a vehicle or a train could improve the vehicle design in order to reduce drag (i.e. reduce fuel consumption) and also could improve the handling quality. This in turn will improve road safety which is beneficial to the public.


High-Speed Aerospace Vehicles

Prof. Konstantinos Kontis

Description

The design and development of high speed transports include a number of challenging phenomena and interactions: transition, SBLI, plumes, high speed intakes and sonic boom. The proposed research will address a combination of these phenomena using a range of wind tunnel facilities, advanced flow diagnostics and modelling/simulation tools. The effects of turbulence, instabilities and contamination will be assessed. Active and passive flow and flight concepts will be tested. The research feeds directly to the development of future aerospace vehicles and transport concepts.


Low-Speed High-Lift Lamda Wings and their Control

Prof. Konstantinos Kontis

Description

The project will involve research to study the fundamental flow physics and aerodynamic effectiveness of novel configurations and platforms using low-speed wind tunnels, and advanced flow diagnostics and instrumentation. The investigation will be supported by numerical simulations and theoretical analysis including multi-disciplinary design optimisation and uncertainty quantification techniques. Advanced flow control devices will be employed. The impact of the research will be on the development novel UAVs, HALE, MALE platforms, and will contribute to the design of the next generation of aircrafts.


Single Stage to Orbit (SSTO) Payload Launcher

Prof. Konstantinos Kontis and Prof. Colin McInnes

Description

Mission and trajectory studies will be performed on a variety of SSTO concepts assessing different launching strategies and engine types. Full modelling and simulation of the launcher will be performed assessing its flying quality characteristics over the entire flight domain. Altitude, Mach number, and angle of attach profiles will be investigated. Advanced optimisation techniques will be utilised, and refinement of available aero-database will be conducted.


Interaction of Engine Exhaust Flows with Surfaces for VSTOL and Space Applications

Prof. Konstantinos Kontis and Dr. Craig White

Description

The global objective of this activity is to investigate engine exhaust flows with surfaces at a fundamental level using computational tools and experimentation. An assessment of the scaling phenomena, ambient, vacuum effects and pulsing of flows will performed on a variety of surfaces. The impact of the research programme will be on the development of VSTOL aircrafts, ascending/descending vehicles etc.


Powered Plasma Manifolds for Intakes, Ducts, Exhausts and External Flows

Prof. Konstantinos Kontis and Dr. Craig White

Description

Advanced DBD (Dielectric Barrier Discharge) and Nanopulse plasma actuators will be developed to provide better control authority for intakes, ducts, mixers, exhausts and external flows for both low and/or high speed applications. This is a joined experimental and computational campaign that will improve the plasma flow coupling performance. It is part of an on-going international collaboration. The expected impact of the proposal is in the following three areas: 

a. Aerodynamic design and performance assessment of vehicles; 

b. Manipulation of noise characteristics and signature;

c. Combustion.


Rotor wake in the vicinity of an obstacle

Dr. Richard Green and Prof George Barakos

Description

Helicopters are versatile aircraft that often operate in challenging environments. Of particular concern is flight near the ground or obstacles, where the rotor aerodynamics can become far more complex than in free air and the pilot workload is higher. There is a clear lack of information available about these types of flows, and unexpected phenomena may occur during practical helicopter operations, which have accounted for the loss of many lives and airframes. Improved designs and operating procedures can only be the result of more information, and the purpose of the project is to investigate the rotor wake aerodynamics when the rotor is close to an obstacle. This shares many of the characteristics of the flow in free air and the flow close to the ground, and the emphasis of the project is to investigate what happens as the rotor clearance from the obstacle changes. One of the uniquely challenging aspects of rotor aerodynamics is that the flight mechanics and aerodynamics are intimately linked, and this is rotor aeromechanics. Thus it is not enough to investigate the flow alone, but to gather data pertaining to the rotor state that can in turn be used for flight simulation and handling qualities assessments. This requires the use of specialist rigs and measurement techniques that can provide a complete picture of the control state of the rotor and the flow field.

The objectives of the project are, through the use of appropriately instrumented rigs and measurement techniques, to perform an investigation of the flow field of the rotor in a variety of rotor/ obstacle configurations, to assess the trim state of the rotor and the control inputs required to achieve trim under these conditions, assess loads exerted on the obstacle by the rotor wake, and relate observations of the flow to the changes of rotor trim state, to anticipate vehicle behaviour in these circumstances. Major achievements will be an improved understanding of the rotor wake in a particularly challenging scenario, information for the rotorcraft operating and simulation community about the controls required, and the generation of a database of flow field measurements to inform the wider rotorcraft community worldwide. This will be a unique experiment of interest to a candidate who wishes to become an expert in the particularly challenging area of rotor aeromechanics, and has a primary interest in experimental techniques.

The successful researcher will publish articles in journals such as Experiments in Fluids, Journal of the American Helicopter Society, AIAA Journal, and is expected to present work at major international conferences in the EU and USA.


Tail rotor blockage effects

Dr. Richard Green and Prof George Barakos

Description

The performance of a tail rotor of a helicopter is critical to the operation of the flight vehicle. A tail rotor is often mounted in the vicinity of a tail empennage consisting of a fin and horizontal elevator. Rotor performance is well know to be affected by the presence of a surface nearby, and practically all research effort in this respect has been concerned with ground effect, where the helicopter is flying close to the ground. The presence of a tail fin close to a rotor would constitute a partial ground effect, but there are many variables to consider. What is surprising is that there is very little in the literature about the effect of tail rotor blockage on a tail rotor performance, and this research project aims to address this.

Experimental work will be conducted in the deHavilland wind tunnel using rotor systems available. Small fin models will be constructed and instrumented with surface pressure tappings, and rotor system pressures, loads and flow field data will be measured using the instrumentation available with the wind tunnel.   One of the objectives of the project will be to use the data obtained from the wind tunnel tests to improve the tail rotor load predictions used in rotorcraft simulation models.  In many simulations simple correction factors are used to modify the predicted tail rotor loads to account for the proximity of the fin.  To date there has been insufficient experimental data available to refine this approach to take into account different tail rotor positions, fin shapes or separation distances, all of which can affect tailrotor blockage.  One of the anticipated outcomes of this research will be the development of guidelines for more accurate empirical modelling of tailrotor loads.

The successful researcher will publish articles in journals such as Experiments in Fluids, Journal of the American Helicopter Society, AIAA Journal, and is expected to present work at major international conferences in the EU and USA.


Experimental and numerical investigation of waverider vehicles with realistic leading-edge and aerodynamic control surface designs

Dr. Rene Steijl and Prof. Kostas Kontis

Description

The design and development of aircraft capable of flying at hypersonic speeds involves many challenges, including complex aerodynamic phenomena, creating an effective propulsion system as well as managing the thermal environment created at high speeds and the associated challenges to the thermal protection system, structure and materials.

The proposed research considers designs of the wave-rider type, with a shape optimized for efficient cruise flight. The relatively high aerodynamic efficiency of such configurations, however, is achieved using a sharp wing leading edge, which in high-speed flight creates unacceptable heat transfer rates. Also, the ideal wave-rider shape has no provision for engine installation and aerodynamic control surfaces and its aerodynamic stability is typically too marginal for practical use.

In the proposed research, the latest in-house developed Computational Fluid Dynamics methods will be used to create a realistic wave-rider design, with leading-edge bluntness and suitable tail/fin surfaces for enhanced stability at a range of speeds.

Then, the aerodynamics of the wave-rider vehicle at Mach 7 will be investigated in the high-speed wind tunnel at Glasgow University.  Advanced flow diagnostics will be used to analyse the flow in detail, while the loads on the vehicle will also be measured.

The main aims are to assess the aerodynamic performance and stability of the vehicle with the employed leading edge design and aerodynamic control surfaces. The combined experimental and numerical flow field data will provide detailed insight into the controls-surface effectiveness as well as the heat transfer into the vehicle surface. The results will be used to improve stability and control of improved designs. The project will make contributions to making wave-rider derived designs a more realistic prospect for future aircraft and space launch systems.