Abstract
Numerical predictions and measurements of the flow structure and the Nusselt number behavior are presented for the endwall region of a linear blade cascade with contoured leading edge fillets. Two types of fillet profiles are employed: (a) a linear profile and (b) a circular profile. The fillets are placed at the junction of the blade leading edge and bottom endwall. The results with the fillets are also compared with the baseline case (predicted and measured) without any leading edge fillet. The pitchwise pressure gradient and shear stress on the endwall region are reduced for the filleted blades compared to the baseline case where there is no fillet. The flow turning from the axial direction (yaw angle) and the pitchwise flow velocity at the endwall boundary layer are also reduced in the vicinity of the fillets. In addition, the fillets weaken the leading edge horseshoe vortex by significantly reducing its vorticity and turbulent kinetic energy. Because of such changes in the endwall boundary layer, especially in the region where the fillets are located, the streamwise vorticity, turbulence kinetic energy, and total pressure losses in the passage vortex and the suction side leg vortex are reduced compared to the baseline. Endwall Nusselt numbers for the filleted cases are reduced upstream of the throat region.