US Patent 11560797 Endwall contouring for a conical endwall

A turbine stage includes an array of airfoils spaced apart circumferentially to define a flow passage therebetween for channeling a working medium. The airfoils extend radially outward from an inner endwall located at a hub side thereof. The inner endwall is inclined at an angle to an engine axis such that the flow passage is divergent from an upstream side to a downstream side. The inner endwall is non-axisymmetric about the engine axis, having a mid-passage bulge located between circumferentially adjacent first and second airfoils. The bulge has a peak at a position between 20-60% Cax