A numerical method for 3D calculations of turbomachinery flows

This paper describes a method for the calculation of 3D viscous compressible (subsonic or supersonic) flow through blading systems in axial turbomachines. The governing equations are written in the form of thin-layer Reynolds-averaged Navier-Stokes equations with turbulent effects simulated by means of a modified algebraic model of Baldwin-Lomax. The numerical scheme is that of Godunov-type upwind differencing and ENO reconstruction suggested by Harten so as to assure monotonicity preserving and high accuracy of computational results. The computational efficiency Is achieved thanks to the Implementation of a simplified H-type multigrid approach and delta -form implicit step. The described method also incorporates tip leakage above unshrouded rotor blades. A software package FlowER to calculate 3D flow in multi-stage turbomachines developed based on this method allows us to obtain local characteristics, like temperature, pressure, density or velocity distributions, as well as global characteristics, like flow rates, stage reaction, flow efficiency for the considered turbine/compressor stage. The presented results of calculations Include an HP model cascade and LP stage of a steam turbine, with some comparison of experimental data and computational results.