六单元圆转方塞式喷管冷流试验与分析

对六单元圆转方塞式喷管的性能以及内喷管间隙与塞锥侧板的影响情况进行了冷流试验,利用纹影显示技术得到了地面、中空和高空三种工作高度下的流场结构。结合塞锥表面压强的计算结果和试验效率曲线,分析了内喷管单元间隙和塞锥侧板对性能的影响,单元之间有间隙和无塞锥侧板均会一定程度地降低喷管性能。结果表明,从地面到高空,六单元圆转方塞式喷管试验模型具有一定的高度补偿能力,其中无单元间隙有塞锥侧板的模型的推力系数效率在0.90~0.95之间变化。但设计高度下的效率低于理论预期值,其性能损失主要是圆转方内喷管型面、塞锥截短、多单元出口激波、底部不封闭等原因造成的。

Cold-flow tests and analysis of linear clustered plug nozzles with six round-to-square inner nozzles

Air cold-flow tests on the linear clustered plug nozzles with six round-to-square inner nozzles were carried out to investigate the altitude compensation characteristic and effects of gap between modules and plug sidewall on the nozzle performance.The plug flow fields at sea level,middle altitude and high altitude are presented using schlieren technique.Combining the plug surface pressure profiles by numerical computation with the experimental data,effects of gap between modules and plug sidewall on the nozzle performance are also studied.The test results show that the plug nozzle models are capable of altitude compensation and the thrust coefficient efficiency of the best model is in the range of 0.90~0.95 from low to high altitude.The nozzle efficiency at design altitude is about 0.95,which is under the theoretic prospective.The performance loss is caused by the round-to-square inner nozzle contour,the plug truncation,multi-module effect,the opened plug base,etc.