矩形内喷管塞式喷管的数值计算与实验研究

Numerical and Experimental Study of a Plug Nozzle with two Rectangular Inner cells

为了了解内喷管为二维矩型的塞式喷管性能,设计了一个二单元的实验塞式喷管,并对模型进行了数值模拟和实验研究。数值模拟采用无波动、无自由函数耗散(NND)差分格式求解三维NS方程,利用空气冷流实验方法评价了喷管性能。研究模型的内喷管喉部面积为4×60mm2,内喷管面积比为4,总面积比为24.05,设计压力比为500。计算得到了正确的流场结构和塞锥表面压强分布,结果与实验数据吻合很好,效率数值最大相差1%。模型的性能也比较理想:最大的推力系数效率为0.995,同钟型喷管相比,具有很好的高度补偿能力:从地面到高空,推力系数效率在0.97～0.995之间变化。不同压强比下全锥塞式喷管的塞锥表面压强分布规律,可以作为研究截短型塞式喷管塞锥压强分布的基础。

In order to understand the high performance of the plug nozzle with two-dimensional rectangular inner cells, a two-cell test plug nozzle was designed, and numerical and experimental studies were conducted. The numerical simulation is based on an non-oscillatory and non-free parameters dissipation difference scheme to solve the three-dimensional Navier-Stokes equations, and the cold flow experimental studies using air were performed to evaluate the nozzle performances. The model has a nozzle throat area of 4×60 mm2, with the inner nozzle area ratio of 4 and total area ratio of 24.05. The nozzle was designed for the pressure ratio about 500. The flow field and plug pressure profiles were obtained. The results show a good agreement with experimental data, and the maximum discrepancy is by 1%. The model has high nozzle performance with the maximum thrust coefficient efficiency of 0.995, and has good altitude compensation characteristic as compared with the bell nozzle that the nozzle efficiency is in the range of 0.97-0.995 with the pressure ratio changing from 45 to 600. The plug surface pressure profiles for the full-length plug nozzle at different NPR (the ratio of combustion chamber pressure to ambient pressure) can provide valuable data for researching the truncated plug nozzle.