Endwall Contouring Optimization in a High Pressure Turbine Vane With Consideration of Rim Seal Flow
In this paper, non-axisymmetric endwall contouring optimizations in a high pressure turbine second vane passage were performed with and without including the rim seal flow. Aerodynamic performances of two contoured endwalls were studied and compared with the planar endwall case. The optimization was carried out with a commercial software package NUMECA Fine/Design 3D. A genetic algorithm was chosen as the optimization method. The objective was to minimize the total pressure loss in the high pressure turbine vane. Without the rim seal flow, the contoured endwall decreased the strength of the passage vortex, and reduced the total pressure loss coefficient up to 10.4%. However, the benefit achieved by this contoured endwall was lost when the rim seal flow was included by adding a under platform section in the computation model. With the existence of the rim seal flow, the flow field near the endwall was significantly changed. After recontouring the endwall using the optimization procedure with including rim seal flow, a 9.8% decrease in total pressure loss coefficient was achieved with the reduction of the vortex strength.