内冷通道特性对外表面气膜冷却换热影响研究

The Effect of Internal Cooling Channel on the Heat Transfer of Outer Surface Film Cooling

采用混合网格和realizablek-ε紊流模型,求解三维N-S方程,对气膜孔入口无横流、仅有横流和横流通道中有扰流肋的情况下,外表面气膜冷却换热特性进行了数值研究。具体分析了横流及肋的存在对气膜冷却外表面换热系数的影响。结果表明,横流及肋的存在使通道流场变得非常复杂,横流提高了外表面的换热系数,且使流动及换热呈现不对称特性分布;而扰流肋的存在减弱了横流对外表面的影响,换热系数相对于仅有横流时降低,且使外表面流动及换热的对称性有所改善。

Unstructured mesh and realizable k-ε model were used carefully to study the heat transfer characteristics under three flow configurations at the entrance of film holes： no crossflow, only crossflow and crossflow with rib turbulators. In- vestigation was focused on the influencies of crossflow and rib turbulatores on the heat transfer coefficients on the outer sur- face with film cooling. The results show that the flow filed becomes complicated under the existence of the crosscurrent and rib tubulators, and crossflow strengthened the heat exchange on outer surface. The former results in the dissymmetry of flow and heat exchange of outer surface, but the latter is exactly the opposite.