Session: 13-05 External and Internal Flow Heat Transfer II

Paper Number: 83024

83024 - Development of a Large-Scale High-Speed Linear Cascade Rig for Turbine Blade Tip Heat Transfer Study 

The high-speed Over-Tip-Leakage (OTL) flow has significant impact on aerodynamic performance of the turbine and generates high thermal load for the High-Pressure turbine (HPT) blade tip. Different tip sealing and cooling design strategies are applied to reduce the OTL loss and help turbine survive in high temperature environment. High-speed linear cascade experimental rigs play an important role in understanding flow physics and evaluating their performance. Multiple blades and passages are often required to maintain a reasonable flow periodicity. For tip heat transfer experimental study, a scale-up test model is always desired for a closer match of the engine Reynolds number, and more importantly, better measurement resolution and accuracy, especially around the trailing edge, squealer rim, and cooling holes. However, a high-speed multi-passage cascade design with scale-up test blade model demands more compressed air supply. It can also become very difficult for most research laboratories to afford the large amount of heating power if the engine condition wall-to-gas temperature ratio needs to be matched. To conduct heat transfer measurement, it is possible to achieve the same aerodynamics over the tip region with a reduced number of blade passage, because in such case, there is no need to satisfy the downstream flow periodicity. A simplified three-passage linear cascade rig for tip heat transfer research is developed in this study. Both the design method and the rig performance are presented. With optimized side wall profile design, adjusting tailboard, and more importantly, an assisting blade with adjustable tip gap, it was found that same near-tip region blade loading as the periodic case can be achieved, as well as the OTL vortex and passage vortex interaction. The numerical findings were validated by real rig thermal measurement. The enlarged test model offers much more improved resolution of optical measurement near the tip region.

Presenting Author: Hongmei Jiang Shanghai Jiao Tong University

Presenting Author Biography: RESEARCH INTERESTS<br/>(1) Gas Turbine heat transfer and cooling technology<br/>(2) Aerodynamic and heat transfer testing methodology<br/>(3) Thermal management<br/><br/>EDUCATION<br/>Ph.D. Power Engineering and Thermophysics, Shanghai Jiao Tong University (2018)<br/>M.S. School of Energy and Power Engineering, Yangzhou University (2011)<br/>B.S. School of Energy and Power Engineering, Yangzhou University (2008)

Authors:

Hongmei Jiang Shanghai Jiao Tong University
Wenbo Xie Shanghai Jiao Tong University
Shaopeng Lu Shanghai Jiao Tong University
Xu Peng Shanghai Jiao Tong University
Yongmin Gu Shanghai Jiao Tong University
Qiang Zhang Shanghai Jiao Tong University