Computer codes which solve the Reynolds-averaged Navier-Stokes equations are now used by manufacturers to design turbomachines, but there is no consensus among experts about which grids and which turbulence models are good enough to provide a reliable basis for design decisions. The AGARD Propulsion and Energetics Panel set up a Working Group to help to clarify these issues, by analysing predictions (using as wide a range of codes as possible) of two representative but difficult single blade row test cases: NASA Rotor 37 and an annular turbine cascade tested by DLR. This paper summarises the Group’s results and conclusions.
Recommendations are made about the type and density of grid, which depend on many factors. Although mixing-length turbulence models give good results for quasi-two-dimensional boundary layers, they are essentially unsuitable for turbomachines with their complex end wall flows; it is essential to adopt some kind of turbulent transport model.
