层板结构冷却机理的数值模拟研究

Numerical investigation of cooling mechanism of laminate porous plates

应用商业软件对一种典型的层板结构选取多个单元进行了流动和换热的耦合计算,考虑了燃气侧及冷气侧流动的影响,燃气及冷气的流动方式模拟层板叶片中真实的流动方式。网格划分采用非结构性网格,湍流模型采用k-ω双方程模式,速度与压力采用SIMPLE算法耦合求解。获得了层板内部的流动和换热情况,流体域、固体域的温度信息。发现冲击孔及气膜孔内部的流动不具有对称性,各换热面的换热系数分布也不均匀,燃气侧局部区域出现负热流现象。分析了层板燃气侧、内部及冷气侧的流动和换热特性及其对层板冷却有效性的影响,得到了层板冷却有效性随吹风比变化的曲线。

Coupled fluid/ solid heat transfer calculation was performed to obtain the temperature distributions, the complex flow and heat transfer patterns in the laminate plate using the commercial codes FLUEN6. 1. Unstructured meshes were used in the whole unit. The κ- ω turbulence model was carefully selected to gain better local heat transfer characteristics. The result showed that the flow in the impingement holes and the film holes was asymmetry, the heat transfer coefficients were non - uniform on all the walls, and even negative heat flux was existent downstream of the film holes. The effects of blowing ratios on the impingement cooling and film cooling were analyzed to get the effect on the cooling effectiveness of lamilloy.