套筒长度对火焰筒流场和雾化特性的影响

利用激光粒子动态分析仪实验研究了套筒长度对火焰筒头部的流场和喷雾场的影响.结果表明:套筒长度控制流场的发展,影响顺流区壁面再附点的位置,随着套筒长度的增加,再附点向下游移动.套筒的长度存在一个临界值,使中心回流区的尺寸最大.套筒对雾化的影响较大,在回流区内,套筒长度最小时雾化效果较好.在顺流区内,液雾的索太尔平均直径随着套筒长度的增加而逐渐减小.套筒加长时喷雾锥角有所减小.套筒的最佳长度选择需要综合考虑燃烧室的具体设计要求.

Experimental study the effect of flare sleeve length on the flowfield and spray characterization of a combustor swirl cup

The two-phase flow field of combustor dome with double swirlers,venturi and flare sleeve was studied experimentally using two-dimensional particle dynamics analyzer(PDA).The velocities,diameter,volume flux of droplets were measured,while the effects of the flare sleeve length on the flow field and atomization were analyzed.The flowfield downstream created by flare sleeves with different lengths is of the same structure,which includes central recirculation zone and corner recirculation zone.The flare sleeve length controls the development of flow field and affects the attachment point of the flow,which moves downstream with the increase of the length.The size of the recirculation zone is biggest when the flare sleeve length reaches a critical value.The Sauter mean diameters(SMD) produced by the shortest flare sleeve are smallest in the recirculation zone,showing good atomization.The atomization improves outside the recirculation zone with the increase of the flare sleeve length.The spray cone angle decreases with the increase of the flare sleeve length.The selection of the optimum sleeve length depends on the needs of combustion performances.