Three-dimensional rotational inviscid flow calculation in axial turbine blade rows

A method to compute three dimensional, rotational, adiabatic, inviscid flow of a perfect gas in an axial turbine blade row or an axial turbine stage (subsonic, transonic, or supersonic) is presented. In low subsonic, rotational flow calculations in isolated cascades, the method reveals the main secondary effects. Inside the passage, agreement between computed and measured static pressure and angle distributions is fairly good. For transonic flow calculations in axial turbine stages, the method uses a time-averaged blade row interaction model. The mass flow and the overall aerodynamic characteristics of both blade rows are well predicted. Real three dimensional effects, such as lack of stream surface axial symmetry, are clearly seen from the calculated results. Contrary to over an isolated blade row calculation, the interrow boundary conditions adapt themselves automatically to the flow pattern, no experimental data being built in to the calculation.