应用Realizable k-ε紊流模型并结合SIMPLEC算法,近壁区流动的处理采用加强壁面函数法,对涡轮叶片前缘多孔气膜冷却进行数值模拟,探讨流线分布与冷却死区范围变化的关系。结果表明,叶片前缘压力面侧布置的气膜孔对叶片压力面有很好的冷却效果;从叶根位置气膜孔出流的冷却气流由于受到叶栅轮毂的影响而改变原有流动轨迹,造成叶片根部存在较大范围的气膜冷却死区;较大的射流比可以对叶片中部前缘部分形成较好的气膜冷却效果,有效地消除气膜孔间冷却死区;射流比的变化对叶根位置叶片前缘冷却死区减小无影响。
Using the Realizable k-ε turbulence model, SIMPLEC algorithm and the enhanced wall treatment, numerical simulation was performed to investigate in multiple holes film cooling at leading edges of turbine blade. Relationship between streamline distributing and cooling deterioration area was discussed. The results show that the cooling effectiveness on concave side is better than suction side with laying film cooling holes in concave side at leading edges of turbine blade. Because the cooling airflow from the film cooling holes at root in the blade head changes its contrail in the influence of the hub, the cooling deterioration area increases at root in the blade head. The cooling effectiveness at mid-spanwise in the blade head increase in the case of high flow ratio so that the cooling deterioration area is avoided effectively. The cooling deterioration area doesn't almost vary with changing flow ratio.