射流孔交错偏置排布下的楔形凹表面对流换热数值研究

通过三维数值模拟的方法研究了射流孔交错偏置排布下的楔形凹表面对流换热，在射流孔偏置间距比（L/d）为0~2.5、射流孔距凹腔前缘间距比（H/d）为6~12、射流冲击雷诺数（Re）为10000~28000的研究参数下，研究结果表明射流孔交错偏置排布在凹腔中诱导复杂的涡流，对应于射流冲击驻点区的局部表面传热系数得到增强；相对于直线排布的射流孔，小射流孔交错偏距比能够使得凹腔前缘附近沿弦向的展向平均努塞尔数相对射流孔直线排布方式有所改善，随着射流孔交错偏距比增加，沿弦向的展向平均努塞尔数最大值所对应的弦向位置逐渐向凹腔前缘下游迁移.为了在保持凹腔前缘对流换热能力不受到显著削弱的前提下，改善凹腔前缘附近的射流冲击对流换热能力，射流孔交错偏距比宜选择在1倍射流孔直径左右. 

Numerical investigation of convective heat transfer on a wedge-shaped concave surface subjected to staggered offset impinging jets

Three-dimensional numerical simulations were conducted to investigate the convective heat transfer on a wedge-shaped concave surface subjected to staggered offset impinging jets. Under the presented parameters, such as offset spacing ratio (L/d) of 0-2.5, jet to concave leading edge spacing ratio (H/d) of 6-12, and jet Reynolds number (Re) of 10000-28000, the results showed that staggered offset of the impinging jets introduced complicated vortex flow inside the concave cavity and enhanced the local heat transfer correspondingly to the impingement stagnation zone. By comparison with the jets arranged in a line, relative little staggered offset of the impinging jets enhanced the laterally-averaged Nusselt number in the vicinity of concave leading edge. With the increase of offset spacing ratio, the chordwise location corresponding to the maximum laterally-averaged Nusselt number moved downwards. To improve the laterally-averaged Nusselt number in the vicinity of concave leading edge while maintaining local heat transfer capacity at the leading edge, the offset spacing ratio of 1 approximately is more appropriate.