冲击/发散复合冷却方式发散壁换热系数研究

对航空发动机的一种先进冷却方式,冲击/发散复合冷却方式的发散壁燃气侧换热系数进行了试验研究。考虑了影响燃气侧换热系数的流动和几何参数,它们是主流雷诺数、吹风比以及几何结构。采用比较法研究燃气侧换热系数,基准换热系数与经典传热准则计算值相比,精度在±7%以内。研究发现主流是充分发展湍流时,主流雷诺数对发散壁燃气侧换热系数基本无影响,而吹风比和几何结构是主要的影响因素。多排气膜叠加,也使得换热增强系数沿流向增加。对实验结果总结了经验关系式,可以用于该种冷却结构的传热设计和校验。

Study of the Effusion Wall Film Heat Transfer Coefficients of Impingement/Effusion Double Wall Cooling Method

This paper presents the experimental study of effusion wall film heat transfer coefficients for impingement/effusion double wall cooling method,which is one of the advanced cooling methods of combustor liner in aeroengine.The investigation focused on the factors affecting the heat transfer coefficients,which are main flow Reynolds number,blowing ratio and configurations.The heat transfer coefficients were studied using the comparing method,and the basic heat transfer coefficients were compared with classical heat transfer result,showing that the difference was within ±7%.The experimental results showed that the main flow Reynolds number had no effect on the effusion wall film heat transfer coefficient,while the blowing ratio and configurations were the main factors.The more the rows of cooling film,the higher the heat transfer coefficient along the flowing direction.The experimental results were correlated,and the correlation can be used in the heat transfer design and validation of cooling schemes.