新型双层壁隔热屏气膜板内壁面换热特性数值研究

Numerical Investigation on Internal Heat Transfer Characteristic of Film Plate in a New Double-Wall Liner

关键词:  双层壁  加力燃烧室  隔热屏  内换热  数值计算

Key words:  Double-Wall  Afterburner  Liner  Internal Heat Transfer  Numerical investigation

摘要:

为了研究加入二次倾斜冲击后双层壁隔热屏内通道的流动特征和换热分布，通过数值模拟研究了不同冲击距离和不同中间孔直径下，冲击雷诺数在2500~7500，气膜板内壁面的换热系数分布特征。结果显示:冲击距离越短，高换热区域面积越大，平均换热系数越高；冲击距离对气膜孔所在环腔内的二次冲击和旋流之间的相互作用影响较大；中间孔直径越小，平均换热系数越高，气膜孔所在的环腔内二次冲击范围越小，漩涡冲击范围越大。

Abstract:

Numerical simulation was carried out to study the internal flow and heat transfer characteristics of the double-wall afterburner liner which was added with second oblique impingement. Internal heat transfer coefficient distribution on the film plate was investigated at different impingement distances and different middle-hole diameters in the Reynolds number range of 2500~7500. The results show that the region with high heat transfer extends and the area-average Nusselt number increases with the decrease of the impingement distance. The interaction of the second impingement and the vortex flow in the cavity where the film holes were located is mainly influenced by the variation of the impingement distance. In the cavity where the film holes were located，the region with the vortex impingement increases and the region of the second impingement decreases with the decrease of the middle-hole diameter. The area-average Nusselt number increases with the decrease of the middle- hole diameter.