非均匀入口与化学非平衡效应对尾喷管性能的影响研究

Non-Uniform Entrance and Non-Equilibrium Chemical Effects on Scramjet Nozzle Performance

关键词:  超燃冲压发动机  非均匀流动  化学非平衡效应  喷管性能 

Key words:  Scramjet  Non-uniform flow  Non-equilibrium chemical effect  Nozzle performance

摘要:

基于煤油燃料超燃冲压发动机尾喷管,对均匀入口和非均匀入口、冻结流动模型和化学非平衡模型下的尾喷管内流动进行数值模拟,采用两方程RNG k-ε湍流模型对三维NS方程组进行求解,获得非均匀入口与化学非平衡效应对尾喷管性能的影响。计算结果表明,尾喷管内流动非均匀性由尾喷管非对称膨胀和燃烧室出口非均匀等因素构成,尾喷管入口流动参数非均匀分布对尾喷管推力、升力及俯仰力矩均有影响,算例中非均匀入口使得尾喷管净推力相对于均匀入口增加了1.2%左右；尾喷管性能受化学非平衡效应的影响,非平衡流动模型下的其净推力计算结果相对于冻结流动模型增加3%~4%。 

Abstract:

Using frozen and non-equilibrium chemical 3D models, kerosene-fueled scramjet nozzle flow was numerically simulated with a uniform or non-uniform entrance and RNG k-ε turbulence model, in order to obtain the effects on the nozzle performance. The numerical results show that the non-uniformity of nozzle flow is composed of asymmetric expansion and non-uniform distribution in the entrance which has effects on the nozzle thrust, lift and pitching moment. Compared to the uniform entrance, the nozzle thrust increases about 1.2% with a non-uniform entrance according to the simulated results. The non-equilibrium chemical effect to the nozzle performance is visible. The numerical value of nozzle thrust with non-equilibrium chemical model is 3%~4% greater than that with frozen model. 