Aerodynamic Improvement of Centrifugal Compressors

航空发动机技术的进一步改进对于航空运输业应对不可避免的燃料价格上涨、竞争和环境压力至关重要。离心式压气机在这一改进中可起主要作用，它的每级压力比比目前大多数飞机发动机中使用的轴流式压气机高出上级多。 实际上，用单个离心压缩机级代替许多轴向压缩机级将导致更简单、更短和更轻的航空发动机。然而，离心压缩机的气动性能和技术必须接近轴流压缩机。拟议的研究将建立在轴流压缩机技术的经验和发展的基础上，以显着改善离心压缩机的空气动力学，以更广泛地用于航空推进。它将寻求提高离心式压缩机的绝热效率和失速裕度，以及减少这些参数随发动机寿命的退化。建议通过调查和理解流动物理学并通过使用具有开创性的成本效益的方法开发有效的设计和流动控制策略来实现这一目标，该方法利用了增材制造（3D打印）技术的快速发展。*** 首先，增材制造技术允许探索高度复杂的设计，这些设计在标准制造技术中是不实用或不可能的。此外，聚合物3D打印技术允许快速制造相对便宜的测试装置。拟议的研究将依赖于低成本的全仪表化旋转离心压缩机钻机，这些钻机由大型高年级本科生团队在两个学期的最后一年设计项目课程中定制设计和3D打印建造，该课程已成功生产压缩机钻机三年。从第一台新装置获得的测试数据将用于验证计算流体动力学（CFD）模拟工具，以捕获离心压缩机中的复杂流场。研究生将使用该模拟工具，沿着分析建模，以阐明/理解与所研究的三个方面相关的流动机制，并预测空气动力学改进策略的效果。然后，第二个新装置将用于实验验证这些策略。 在这样做的过程中，这项研究将提供大量的HQP在工程的所有三个方面（分析/数值/实验）的成本效益培训，并提供行业在离心压缩机技术的抢手专家，不仅为航空，而且为使用这种技术的各种各样的行业。

A step improvement in aero-engine technology will be crucial for the air transport industry to confront the inevitable increase in fuel prices, competition and environmental pressures. The centrifugal compressor, which has far superior pressure ratio per stage than axial compressors currently used in most aircraft engines, can play a major role in this improvement. Indeed, the replacement of many axial compressor stages by a single centrifugal compressor stage will result in simpler, shorter and lighter aero-engines. However, the aerodynamic performance and technology of centrifugal compressors must be brought close to that of axial compressors. The proposed research will build on experience and developments in axial compressor technology to significantly improve the aerodynamics of centrifugal compressors for wider use in aero-propulsion. It will seek to improve the adiabatic efficiency and stall margin of centrifugal compressors as well as reduce the degradation of these parameters with engine age. It is proposed to do so through investigation and understanding of the flow physics and developing effective design and flow control strategies by using a pioneering cost-effective approach that takes advantage of the rapid evolution in additive manufacturing (3D printing) technology. *** First, additive manufacturing technology allows for the exploration highly complex designs that were not practical or possible with standard manufacturing technology. In addition, polymer 3D printing technology allows for fast fabrication of relatively inexpensive test rigs. The proposed research will rely on low-cost fully instrumented rotating centrifugal compressor rigs custom designed and built with 3D printing by large teams of senior undergraduate students in a two-semester final-year design project course that has successfully produced compressor rigs for three years. The test data obtained from the first new rig will serve to validate a computation fluid dynamics (CFD) simulation tool to capture the complex flow field in centrifugal compressors. This simulation tool will be used, along with analytical modelling, by graduate students to elucidate/understand the flow mechanisms associated with the three aspects studied and predict the effect of aerodynamic improvement strategies. The second new rig will then serve to experimentally validate these strategies. In doing so, this research will provide cost-effective training of a large number of HQP in all three aspects of engineering (analytical/numerical/experimental) and provide industry with sought-after experts in centrifugal compressor technology not only for aeronautics but also for the very wide variety of industries that use this technology.**