UDMH/NTO火箭发动机尾焰流场特性数值仿真

采用AUSM(advection upstream splitting method)空间离散格式，探究了常用的3种k-ε湍流模型和2阶、3阶迎风格式对激波捕捉效果的影响。采用标准k-ε双方程模型和2阶迎风格式对不同高度和不同来流马赫数下的偏二甲肼/四氧化二氮(UDMH/NTO)火箭发动机尾焰流场进行喷管-尾焰流场一体化仿真。复燃反应采用12组分18步化学反应模型，喷管入口参数由热力计算给出。结果表明:随着来流马赫数的增加，波节数逐渐降低；随着飞行高度的上升，尾焰影响区域逐渐扩大；复燃反应造成混合区中的O2、N2质量分数大幅下降，而混合区中O、OH、NO质量分数则有所上升。 

Numerical simulation of flow field characteristics of UDMH/NTO rocket engine plume

AUSM (advection upstream splitting method) spatial discretization scheme was used to explore the effects of three k-ε turbulence model and second，third orders upwind schemes on shock capturing. The simulation of unsymmetrical dimethyl hydrazine/nitrogen tetroxide(UDMH/NTO) rocket engine nozzle and exhaust plume flow-field at different altitudes and Mach numbers was modeled with standard k-ε two equation turbulence model and two order upwind scheme. Afterburning was modeled with 12-component 18-chemical reaction, and the entrance parameters of the nozzle were used by thermodynamic calculation. Results showed that with the increase of flow Mach number, the wave number decreased; the plume affected area gradually expanded with the rise of altitude; afterburning reaction caused the significant decrease of O2,N2 in the mix zone while the contents of O, OH, NO in the mixing zone increased.