Numerical investigation of unsteady flow field in a turbine stage with film-cooling

An computational method based on 3D steady and unsteady N-S solver was adopted to simulate the flow field in film-cooling turbine, which included a finite difference scheme with 3rd order precision and TVD property, domain decomposition method, arbitrarily curved mesh technique and dual time step. The unsteady changes of aerodynamic parameters of the turbine stage with and without cooling were analyzed. The result shows that the influence of the upstream stator cascade trailing flow with cooling on the transonic region near rotor surface is distinctively different from that without cooling. When the upstream stator blade is cooled, the aerodynamic load on rotor blade and the averaged turbine stage effectiveness decreases about 1%, but the periodic fluctuations of the aerodynamic performance in different rotor passages are all reduced apparently.