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

随着航天飞机计划的终止，出现了一个接替其位置的后续战略的挑战。为了使进入太空既可行又负担得起，我们必须在目前对航空航天设计各个方面的理解方面取得巨大的飞跃，尤其是推进系统。我们目前的空间进入系统的这种重新发明带来了需要实施一种新的航天器概念：单级入轨（SSTO）可重复使用运载火箭。它们设法通过消除在发射过程中丢弃部件的需要，大大减少更换部件所需的经常性费用，解决进入低地球轨道的高成本问题。他们成功的一个关键方面是一个推进系统，该系统在整个使命剖面中有效地运行，从起飞到轨道。其中一种方法是联合循环混合发动机，它利用吸气式和火箭模式来实现低地球轨道。然而，由于每种推进模式都有其优点和缺点，因此必须要求发动机在飞行中有效地在模式之间转换，以便在最谨慎的情况下利用每种模式。这需要在其设计中具有高度的复杂性，以最大限度地提高发动机在每个不同阶段的效率。迄今为止，还没有成功运行的可重复使用运载火箭（从地球发射）。因此，将研究工作集中在这些飞行器及其分系统的早期设计上是合理的。泰勒博士最近在这方面的工作特别强调了超燃冲压发动机，提出了一种新的工具概念，用于混合动力发动机性能和结构的初始设计和优化，并特别考虑了超燃冲压发动机模式。这项工作是与研究高超音速发动机进气道和总体装配产生的激波模式的复杂行为同时进行的，特别注意它们对燃烧过程的影响。

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.