Study of Vortex Structures in 3D Unsteady Aerodynamics using Experiment and Simulation

With the termination of the Space Shuttle program, the challenge emerges for a successor strategy to take its place. For access to space to be both feasible and affordable, vast leaps forward must be taken in our current understanding of all aspects of aerospace design, not least importantly propulsion systems. This reinvention of our current space access systems has brought about the need for a new concept of spacecraft to be implemented: The single-stage-to-orbit (SSTO) re-usable launch vehicle. They seek to address the high cost of achieving low-earth orbit by removing the need for parts jettisoned during launch, significantly reducing the recurring costs required in their replacement. A key aspect to their success is a propulsion system which operates efficiently across the whole mission profile, from take-off to orbit. One such approach is the combined cycle hybrid engine, which utilizes both air-breathing and rocket modes to achieve low-earth orbit. However, as each propulsive mode has both its benefits and its drawbacks, the engine must be required to effectively transition between modes mid-flight, in order to utilise each mode when most prudent. This requires a high level of complexity in its design to maximise the engines' efficacy in each distinct phase. To date, there has been no successfully operated re-usable launch vehicles (launched from Earth). It is therefore reasonable to concentrate research efforts on the early stage design of these craft and their subsystems. Dr Taylor's recent work in this direction has had a particular emphasis on scramjet engines, with the conception of a novel tool for the initial design and optimisation of both performance and configuration of hybrid engines, with specific consideration for the scramjet mode. This has been conducted alongside investigations into the complicated behaviour of shock patterns generated as a result of the inlet and general assembly of hypersonic engines, with special attention given to their influence on combustion processes.