For the problem in predicting the corner separation

the Spalart-Allmaras (S-A) model was modified by introducing a normalized pressure gradient into the production term of the eddy viscosity in the model equation. Through the calibration in two series of low-speed compressor cascade cases with corner separation

it was found that compared with the experimental results

the original S-A model got a stronger corner separation and lower wall pressure in the separation zone

while the modified model's results were closer to the experience in the size of the separation zone

the pressure coefficient on the suction and pressure sides

etc. The analysis on the production and dissipation terms of the eddy viscosity in S-A model indicates that the normalized pressure gradient introduced to the production term can recognize the separation zone effectively. It can also change the transportation of the eddy viscosity of the model and enhance the eddy viscosity in the corner separation

bringing about a smaller separation zone

while the prediction in the main flow area in the modified S-A model remains the same as the original S-A model. Thus a better prediction is got.