Turbulence modelling analysis in a corner separation flow

Abstract This paper studies RANS turbulence modelling for a linear compressor cascade corner separation flow, using large-eddy simulation results as reference. The Boussinesq and the quadratic constitutive relations are investigated with two versions of Wilcox’s k − ω turbulence model through a priori and a posteriori analyses. In the a priori analysis the quadratic constitutive relation shows improvement on the alignment between the rate-of-strain tensor and the Reynolds stress tensor for the inlet region, compared to the Boussinesq constitutive relation. But the improvement is less significant in the highly vortical region. Using the turbulent kinetic energy and the specific dissipation rate provides a fairly good estimate of the turbulent viscosity. The turbulent kinetic energy budget is also investigated. Large-eddy simulation results present non-equilibrium turbulence, i.e. the production and dissipation are not balanced, whereas the RANS models predicts equilibrium turbulence.