Application of Delayed Detached Eddy Simulation and RANS to Compressor Cascade Flow

Spalart-Allmaras (S-A) model based Delayed Detached Eddy Simulation (DDES) is performed to investigate the flow field in a compressor cascade (NACA64A-905) with experimental data for calibration. The value of the modeling coefficient C_DES in DDES is open for revision and depends heavily on the numerical schemes. The effects of C_DES on the DDES results are studied and an optimal C_DES value is estimated for the specific case, with MUSCL reconstructed Roe scheme incorporated in in-house CFD codes. C_DES value of 0.2 is turned out reliable concerning both accuracy and convergence. S-A model is also performed for comparison. Results from different methods indicate that the time-averaged results by DDES with C_DES of 0.2 are more consistent with the experimental results than those by S-A model. The instantaneous flow field predictions show that DDES is well capable of capturing the unsteady features of the cascade flow, especially the wake mixing process.