Numerical simulation on impingement and film composite cooling of blade leading edge model for gas turbine

In this paper numerical simulation is performed to simulate the impingement and film composite cooling on blade leading edge region. The relative performances of turbulence models are compared with available experimental data, and the results show that SST k–ω model is the best one based on simulation accuracy. Then the SST k–ω model is adopted for the simulation. The grid independence study is also carried out by using the Richardson extrapolation method. A single array of circle jets and three rows of film holes are arranged to investigate the impingement and film composite cooling. Five different blowing ratios and five different film hole spanwise angles are studied in detail. The results indicate that the heat transfer coefficient on the internal surface of turbine blade leading edge increases with the blowing ratio, and slightly changes with film hole spanwise angle. And the external film cooling effectiveness distribution would vary rapidly with the blowing ratio and the film hole spanwise angle. •The performances of different turbulence model are validated.•Effects of blowing ratio and spanwise angle on composite cooling are investigated.•Spanwise angle is more effective to improve film cooling than impingement cooling.•Proper blowing ratio and lower spanwise angle is suitable for cooling design.