Numerical simulations were employed to investigate the performance of the flow fields and heat transfer characteristics of four types of film holes:cylindrical holes,fan-shaped holes,laidback fan-shaped holes and laidback holes,on pressure surface of the turbine vane.Fan-shaped holes were expanded with the lateral divergence angle of 12 degrees compared with cylindrical holes,and laidback holes expanded with the forward divergence angle of 7 degrees.Furthermore,laidback fan-shaped holes were expanded in both directions.Results showed that fan-shaped holes and laidback fan-shaped holes showed the maximum film cooling effectiveness within the range of blowing ratios.When the blowing ratio was 2,the film cooling effectiveness of fan-shaped holes and laidback fan-shaped holes was improved to the greatest extent by 128.9％and 146.9％,respectively,in contrast with cylindrical.Additionally,laidback fan-shaped holes had the largest net heat flux reduction,28.8％higher than cylindrical holes,which indicated the laidback fan-shaped hole was the best scheme.And the forward divergence angle had less influence on the flow and heat transfer characteristics than the lateral divergence angle due to inobvious advantages of laidback holes.Besides,the effect of the film cooling effectiveness on net heat flux reduction was dominant on account of similar distributions of net heat flux reduction and the film cooling effectiveness.
关键词
气膜冷却/传热系数/异型孔/高压涡轮导叶/压力面
Key words
film cooling/heat transfer coefficient/shaped holes/turbine vanes/pressure surface
维普
万方数据