A new low Reynolds number nonlinear K-ε model is presented

in which two correction functions for the near-wall flow and a nonlinear expression for the Reynolds stress are incorporated.Several backstep separated flows with two different expansion ratios are numerically studied by using the above model and a standard K-ε model.In comparision with experimental data

the results obatined show that the predictions of the presented nonlinear model are obviously improved over these of the standard K-ε model in respect of various flow parameters

such as reattachment length

time mean velocities and Reynolds stress components.Also

the presented model is the partial differential Reynolds stress model in prediction of the Reynolds stress components.