Beijing-Moscow Mathematics Colloquium (online)
Abstract
Future aero engines are expected to achieve higher efficiencies and lower emissions, which brings new challenges for turbine designers. In a high-pressure turbine, tip clearances exist between the turbine rotor blade tip and the casing to prevent rubbing. The pressure difference between the blade pressure side and the suction side drives the gas across this tip clearance gap. The high-temperature gas results in excessively high metal temperatures on the blade tip, which lead to thermal erosion and oxidation. Obtaining good aerothermal performance is the key to maintain the performance of the high pressure turbines. The current talk will present a combined experimental and numerical study, which aims to understand the performance of the tip leakage flow and to develop new tip configurations for higher engine efficiency. First, the aerodynamic and heat transfer performance of squealer tips will be discussed. The effects of the squealer height and thickness will be investigated. Then, the tips with
coolant injection are investigated to understand the effects of the cooling air on the loss mechanism and tip heat transfer. Finally, winglet configurations are used on blade tips to reduce the tip leakage loss. The results showed that by using the winglet tip developed in the current study, the turbine stage efficiency increases.
Bio
Chao Zhou is a tenured associate professor and the director of turbomachinery laboratory at the college of Engineering in Peking University, China. Before join Peking University, he obtained his doctorate degree at the Whittle Laboratory of Cambridge University in 2010. He is also educated in Nanjing University of Aeronautics and Astronautics, China, and received his Master degree and Bachelor in 2006 and 2003 respectively. His main research area is the aerodynamic and heat transfer of turbomachinery, including aerothermal performance of high pressure turbines, high-lift low pressure turbines; inter-turbine duct flows, unsteady flows and loss mechanism of turbomachinery, advanced cooling methods and highly loaded compressors. He has published 9 papers on the Journal of Turbomachinery, which is the top Journal in the research area. Dr. Zhou is a member of ASME IGTI Tubomachinery committee. He serves as the review co-chair of 2020 GPPS (Global Power and Propulsion Society) conference.
