二维塞式喷管再生冷却换热的数值模拟

Numerical Simulation of Regenerative Cooling in Two Dimensional Plug Nozzles

为了解塞式喷管再生冷却的换热特性 ,建立了二维型面塞式喷管计算模型 ,采用数值模拟的方法 ,研究了不同工况下塞式喷管的流场和换热特性。计算中 ,假定塞式喷管中的流动为冻结流动 ,考虑燃气向壁面的对流换热和辐射换热 ;采用二阶迎风格式离散控制方程 ,及 DO( Discrete Ordinates)模型离散求解辐射换热方程 ,水蒸气的吸收系数根据 Leckner公式计算。计算结果表明 :内喷管的受热情况最严重 ,需要重点考虑 ;塞锥的热防护随工作状况而改变 ,地面工况下塞锥的受热最严重 ,随着压比的升高 ,塞锥的受热逐渐减轻 ,最后不随环境压强而改变 ;

In order to understand the heat transfer characteristics of regenerative cooling in two dimensional plug nozzle, a computational model was established and numerical simulation was carried out. The flowfield and the heat transfer characteristics of plug nozzle at different ambient pressures were investigated. Nozzle flow was assumed to be frozen, and convective and radiative heat transfer from gas to solid wall was considered. Discretization of the governing equations was performed with two order upstream scheme, and radiative heat transfer equation was solved with Discrete Ordinates (DO) method. Absorption coefficient of water vapor was calculated by Leckner formula. The results show that heat transfer condition internal the nozzle is the worst, and should pay more attention. The heat transfer characteristics on plug surface varies with operating conditions. At sea level condition, heating of the plug is the worst, and with the increase of pressure ratio, it is lessened and at last keeps unchanged with ambient pressure. An unreasonable plug contour design can cause a very high temperature peak on it.