Numerical investigation of transonic axial compressor rotor flows using an improved transition-sensitized turbulence model

Internal flows of transonic compressor rotors National Aeronautics and Space Administration rotor 67/37 are numerically studied through the Reynolds-averaged Navier-Stokes simulations. In view of the drawbacks of Spalart-Allmaras (S-A) model, it is suggested in this paper that a helicity-modified S-A model is coupled with a transition prediction model to improve the reliability and accuracy of the original S-A model for simulation of the transonic compressor rotor flows. The performance of proposed model is evaluated in comparison with other S-A-type models. The results indicate that the helicity modification can suppress the strong vortex structures which are overpredicted by the original S-A model and the inclusion of a transition prediction model can help capture the transition phenomena on both sides of the rotor blade, which as absent when fully turbulent models are employed. The coupled model proves to provide more accurate simulation results for transonic compressor rotors than other models under consideration. In particular, it is argued that the constants in the helicity modification term should be altered as far as different rotors are concerned. The helicity and transition modified S-A model may have a great prospect for turbomachinery simulation due to its favorable prediction accuracy and low computational cost.