The influence of endwall contouring and fillet shapes on the performance of transonic turbine stage nozzle guide vane

The present study is intended to investigate numerically the effect of fillet and axisymmetric endwall shapes on loss reduction in a highly loaded low aspect ratio transonic turbine stage. The fillets and endwall contouring shapes are applied over nozzle guide vanes. The aerodynamic performance of two contoured endwalls with and without fillets are studied and results are compared with the base case (cylindrical endwall). The 3D viscous compressible analysis is carried out using commercial CFD Code CFX-14.5 using SST k-ω turbulence model. Maximum reduction of 30.6% in mass averaged total pressure loss coefficient is achieved for endwall contour having S-type variation along with fillet.