瓦状特征型面塞式喷管三维计算与实验

3-D numerical computation and experimental study for a tile-shaped plug nozzle with characteristic plug contour

关键词:  塞式喷管  喷管效率  高度特性  数值仿真  实验  推力系数

Key words:  Plug nozzle  Nozzle efficiency  Altitude characteristic  Numerical simulation  Experimentation  Thrust coefficient

摘要:

为了进一步了解瓦状塞式喷管的性能,采用NND差分格式求解三维N S方程和空气冷流对6单元瓦状特征型面塞式喷管进行了数值模拟和实验研究。研究模型的内喷管面积比为4,总面积比为40,设计压强比为1047。计算得到了流场马赫数和塞锥表面压强分布、喷管推力系数效率,以及不同压强比下中心平面、过渡平面和边缘平面的塞锥表面压强变化规律。计算结果与实验数据吻合得较好,效率数值最大相差1%。实验塞式喷管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,效率在0 93～0 995之间变化。和以前简化型面的4单元瓦状塞式喷管相比,实验和数值模拟均说明塞锥特征型面的优化设计提高了喷管性能,更充分体现了塞式喷管的高度补偿特性,可以成为未来工程应用的选择方案。

Abstract:

To know more about the high performance of the tile-shaped plug nozzle, a six cells tile-shaped test plug nozzle with characteristic plug contour was designed, and numerical and experimental studies were carried out for the model.The numerical simulation was based on NND scheme to solve three-dimensional Navier-Stokes equations, and the cold flow experimental studies using air evaluated nozzle performance.The model studied here with inner nozzle area ratio of 4 and total area ratio of 40 was designed for the pressure ratio about 1047. The Mach number of flow field, the plug pressure profiles, the nozzle thrust coefficient efficiency were computed, and the plug surface pressure profiles for the three planes at different NPR were obtained.The numerical results show a good agreement with experiment data, and the maximum discrepancy is 1%.The model has high nozzle performance with the maximum thrust coefficient efficiency of 0.995, and has good altitude compensation characteristic, compared with the bell nozzle with efficiency range of 0.93～0.995 and with the pressure ratio from 55 to 2000. Compared with the four cells tile-shaped plug nozzle with simple plug contour, the six cells model has higher nozzle performance through optimized design for the plug contour, which can adequately show altitude compensation characteristic plug nozzles and can be a promising candidate for the future engineering application.