纵向波纹隔热屏气膜孔流量系数的实验

Experimental investigation on discharge coefficient of film holes in a longitudinal ripple insulated liner

针对加力燃烧室离散孔纵向波纹板结构隔热屏,通过改变次流雷诺数（Rec=24×104~33×104）和出流比（S=0.02~0.07）得到了波纹板上不同开孔位置处气膜孔的流量系数.实验结果表明,不同开孔位置处流量系数有很大差异;同一开孔位置处,对于长径比远小于1（L/D≈0.17）的孔,气膜孔和次流通道的动量比对小孔流量系数有很大影响,尤其是在动量比较小的情况下;而在同一动量比下,单纯改变小孔雷诺数或次流通道雷诺数对流量系数影响不大.

For a longitudinal ripple insulated liner with discrete film holes in high-powered aircraft engine,the discharge coefficients of the film holes in different positions of the ripple liner were investigated.The discharge coefficients of coolant injection were obtained in a region of Reynolds number Rec=24×104～33×104,and blowing ratio S=0.02～0.07.The results show：（1）The discharge coefficients differ greatly at various hole array positions.（2） For the hole with a low length-to-diameter ratio（L/D≈0.17） in the same position,the momentum ratio of the hole to secondary fluid has an important influence on the discharge coefficients Cd,especially in the case of small momentum ratio,while the Reynolds number of film hole and secondary flow has little influence on the discharge coefficients Cd.