Turbine Vane Endwall Film Cooling and Pressure Side Phantom Cooling Performances With Upstream Coolant Flow at Various Injection Angles

Abstract

In this paper, the endwall film cooling and vane pressure side surface phantom cooling performances of a first nozzle guide vane (NGV) with endwall contouring, similar to an industry gas turbine, were experimentally and numerically evaluated at simulated realistic gas turbine operating conditions (high inlet freestream turbulence level of 16 %, exit Mach number of 0.85, exit Reynolds number of 1.7 × 106). A novel numerical method for the predictions of adiabatic wall film cooling effectiveness was proposed, based on a double coolant temperature model. The credibility and accuracy of this numerical method were validated by comparing the predicted results with experimental data. Results indicate that the present numerical method can accurately predict endwall film cooling performance and vane surface phantom cooling performance for both the ideal low density ratio (DR=1.2) and the typical high density ratio (DR=2.0) conditions. The endwall film cooling effectiveness, vane surface phantom cooling effectiveness and secondary flow field were compared and analyzed for the axisymmetric convergent contoured endwall at three coolant injection angles (small injection angle of θ = 40°, design injection angle of θ = 50°, large injection angle of θ = 60°), two density ratios (low density ratio of DR=1.2, typical high density ratio of DR=2.0) and the design blowing ratio (BR=2.5), based on the commercial CFD solver ANSYS Fluent.