Validation and Verification of Rans Solvers for Tuda-GLR-Openstage Transonic Axial Compressor

Abstract

This paper presents a comprehensive validation and verification study of turbomachinery Reynolds-averaged Navier-Stokes flow solvers on the transonic axial compressor TUDa-GLR-OpenStage. Two commercial solvers namely Ansys CFX and Numeca FineTurbo are adopted to provide the benchmark solutions, which can be used for verification of other RANS solvers in the future. Based on these solvers, five sets of grids, three advection schemes (i.e., central difference and second-order upwind from Numeca and high resolution from Ansys), two turbulence models (i.e., Spalart-Allmaras and Menter k 􀀀 w Shear Stress Transport) and two rotorstator interface models (i.e., mixing plane and sliding plane) are investigated to quantify their effects on predicting the performance and the flow field of the compressor stage. Some geometric uncertainties and errors including the rotor running tip gap size, the stator hub cavity and the stage throat area change are also discussed. Results show that the choice of grid density and turbulence model is most sensitive to the prediction; the choice of rotor-stator interface model mainly affects the near-tip flow field, but the effect on the overall characteristics is relatively small; the choice of advection scheme has limited effect on the prediction when using a refined mesh. Based on a grid density and an advection scheme with a small discretization error, none of the turbulence models and the rotor-stator interface models can perfectly capture the overall characteristics at the peak-efficiency condition. Possible reasons for the difference between the simulations and the experiment are discussed. The grids and the major CFD results presented in this work are open-accessed to the community for further research. The results and discussions presented in this paper provide a useful reference for future practices of RANS simulations for compressors.