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)在克兰菲尔德大学的航空系统设计、集成和性能方面的全额资助博士生，领域是声学激励和流量控制。本文研究了声激励对高雷诺数边界层流动的影响，以及通过声激励进行流动控制来改善未来航空发动机性能的可能性。这项研究计划为期3年，与劳斯莱斯公司(由劳斯莱斯公司和EPSRC全额资助)密切合作。目前的民用航空发动机部件，如进气口或低压压缩系统，在飞行包线上的各种工作状态下都会出现流动分离。对平板和低弯度翼型的基础研究已经认识到，可以通过利用适当频率和幅度的声波对分离的边界层重新提供能量来实现主动流动控制。该项目将包括量化任何现有的声激励对航空发动机部件性能的影响，并将尝试确定强制激励要求作为燃气轮机应用中的一种主动流动控制手段。这项研究将包括：声激励对剪切流特性影响的基础研究。开发降阶和/或高阶模型以量化现有声激励对发动机部件(进气、低压压缩系统等)性能的影响。开发降阶和/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的任何潜在好处。预计这项工作将包括小规模的实验研究。

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.