“瓦”状塞式喷管的数值模拟与实验

Numerical and experimental study of tile-shaped aerospike nozzles

关键词:  火箭发动机  塞式喷管  高度特性  喷管效率  数值仿真

Key words:  Rocket engine  Plug nozzle  Altitude characteristic  Nozzle efficiency  Numericale simulation

摘要:

为了寻求高性能和更接近工程应用的发动机 ,提出了一种内喷管为轴对称喷管、塞锥为凹面的“瓦”状塞式喷管 ,分析了这种塞式喷管的优缺点 ,并针对一研究模型进行了数值模拟和实验比较。数值模拟采用NND格式求解曲线坐标下的三维平均雷诺的N S方程 ,并用k ε两方程湍流模型封闭方程组 ;实验研究采用酒精和氧气作为推进剂进行了热试车 ;研究模型的内喷管面积比为 3 2 4 ,总膨胀比为 2 2 15 ,设计压力比为 2 2 0。结果显示“瓦”状塞锥改善了塞锥的流场 ,并且当压力比在 16 8～ 2 2 0的范围内变化时 ,其相对理想喷管的喷管效率在 0 90～ 0 96内变化。对发动机设计作进一步改进 ,其性能有望进一步提高

Abstract:

To seek the engine of higher performance,introduced an aerospike nozzle which the thrust cell is axisymmetrical and the plug is concave The advantages and disadvantages of this aerospike nozzle were analyzed at first, and numerical and experimental studies were carried out for such a model The numerical simulation based on the three dimensional Reynolds averaged Navier Stokes equations using low Reynolds number k ε equations closure The oxygen and ethanol were adopted as propellant in the experimental study The model studied here, with thrust cell aero ratio of 3 24 and overall expansion ratio of 22 15, was designed for the pressure ratio about 220 The results indicate that the tile shape plug induce a better flow relatively to conditional plug, and that the nozzle efficiency comparatively to the ideal nozzle is in the range of 0 90～0 96 with the pressure ratio changing from 16 8 to 220 If the contour of the aerospike nozzle is modified, the performance can be improved further