Flow Control through Acoustic Excitation to Improve Future Aero-engine Performance

这是罗尔斯·罗伊斯大学技术中心（UTC）在克兰菲尔德大学航空系统设计、集成与性能领域的一个全额资助的博士奖学金，研究方向是声学激励和流动控制。本博士研究了声激励对高雷诺数边界层流动的影响，以及通过声激励来改善未来航空发动机流动控制的潜力。该研究项目为期3年，与罗尔斯·罗伊斯公司密切合作（由罗尔斯·罗伊斯公司和EPSRC全额资助）。目前的民用航空发动机部件，如进气道或低压压缩系统，在飞行包线的各种运行状态下都会发生气流分离。对平板和低弧度机翼的基础研究已经认识到，通过利用适当频率和振幅的声波重新激活分离的边界层，可以实现主动流动控制。该项目将包括量化任何现有声学激励对航空发动机部件性能的影响，并将试图确定强制激励要求，作为燃气轮机应用中主动流量控制的一种手段。这项研究将包括：声学激励对剪切流动特性影响的基础研究。开发低阶和/或高阶模型，以量化现有声学激励对发动机部件（进气、低压压缩系统等）性能的影响。开发低阶和/或高阶模型，以确定通过强制声激励主动控制分离流对发动机性能产生的任何潜在好处。预计这项工作将涉及小规模的实验调查。

This is a fully funded PhD studentship within the Rolls-Royce University Technology Centre (UTC) in Aero Systems Design, Integration & Performance at Cranfield University, in the field of acoustic excitation and flow control. This PhD investigates the effects of acoustic excitation on high Reynolds number boundary layer flows, and the potential to improve the performance of future aero engines through flow control via acoustic excitation. This research programme spans for 3 years and is in close collaboration with Rolls-Royce plc (fully funded by Rolls-Royce and the EPSRC). Present civil aero engine components, such as intakes or low pressure compression systems, suffer from flow separation during various operating states across the flight envelope. Fundamental studies on flat plates and low-camber aerofoils have recognised that active flow control can be achieved via the re-energisation of separated boundary layers utilising acoustic waves of appropriate frequency and amplitude. This project will involve the quantification of the effects of any existing acoustic excitations on the performance of aero engine components, and will attempt to determine forced excitation requirements as a means of active flow control in gas turbine applications. The study will include amongst other:Fundamental research on the effects of acoustic excitation on shear flow characteristics.Development of reduced- and/or high-order models to quantify the impact of existing acoustic excitation on the performance of engine components of interest (intake, low pressure compression system, other).Development of reduced- and/or high-order models to identify any potential benefits on engine performance arising from the active control of separated flows via forced acoustic excitation.It is anticipated that the work will involve small-scale experimental investigations.