冲击加发散双层壁冷却方式压降分配对斜孔内对流换热影响的研究

 以高推重比发动机燃烧室单位压力单位面积冷却气量为基准,研究了孔数比为1∶1 的冲击/ 发散冷却方式在不同冲击壁和发散孔壁压降分配情况下的发散斜孔内的局部换热系数和平均换热系数。研究发现,压降分配比例的变化对孔进口区( x/ d < 4) 的换热增强有较大的影响。通过CFD 计算孔内的流动,分析了孔进口区换热系数增强的原因。并给出了周向平均换热增强系数的拟合公式,为进一步的换热优化打下了基础。

Influence of Pressure Drop Distribution on the Convection Heat Transfer Inside the Inclined Hole of Impingement/Effusion Cooling

Local and average convection heat transfer coefficients were investigated inside the effusion hole in the impingement/ effusion cooling schemes, which have the hole number ratio of 1∶1, with different impingement wall andeffusion wall pressure drop distributions. The benchmark is the cooling air mass flow rate per unit pressure and areaof the high performance aeroengine. The results indicated that the pressure distribution has great influence on theheat transfer enhancement inside the effusion hole entrance ( x/ d < 4) . The mechanism of the enhanced heat transfer within the effusion hole entrance was explained using a CFD code. The correlation of the circumferential averageheat transfer enhancement coefficients was fitted based on the experiment data, which plays an important role forthe future heat transfer optimum of the impingement/ effusion double skin wall.