Experimental and numerical investigation of high load turbine blade tip cavity structures


 Leakage flow losses are an important factor affecting turbine aerodynamic efficiency. In this paper, experimental and numerical computational studies are used to target three different tips of highly loaded turbine rotor. The single cavity tip formed by squealers is considered as the original cavity tip structure, and based on this, two structures were improved, cavity winglet tip and double cavity combined winglet tip. Five-hole probe and oil flow visualization are used for experimental studies; numerical calculations are used to analyze vortex system structure and loss development. It was found that the double cavity combined winglet tip structure can effectively change the vortex structure inside the cavity and reduce the leakage flow rate. At the same time, the aerodynamic performance has been optimized by 4%.