三维数值模拟再生冷却喷管的换热

Three dimension numerical simulation of heat transfer in regeneratively cooled nozzle

关键词:  液体推进剂火箭发动机  喷管  再生冷却  温度分布

Key words:  Liquid propellant rocket engines  Nozzle  Regenerative cooling  Temperature distribution

摘要:

为了解液体火箭发动机喷管再生冷却的换热特点, 采用数值模拟的方法, 对内喷管燃气、壁面和冷却液建立不同的三维控制方程, 进行流动和传热的耦合计算。在计算中, 假定喷管流动为冻结流动, 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, 采用DO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。计算模型采用缩比热试车发动机, 数值计算结果与实验结果吻合较好, 较准确地模拟出了喷管的壁面热流密度, 得到了喷管燃气和冷却液的流场和温度场, 对高压再生冷却喷管的设计具有指导意义。

Abstract:

To understand heat transfer characteristics of regenerative cooling in liquid propellant rocket nozzle, numerical simulation was employed. Three dimensional governing equations for hot gas, solid wall and coolant were established respectively, and coupled calculation of flow and heat transfer was carried out. In calculation, it was assumed that nozzle flow was frozen, and convective and radiative heat transfer from gas to nozzle wall was considered. Governing equations were discretized with second order upstream scheme and radiative heat transfer equation was solved with Discrete Ordinates(DO) method. Absorption coefficient of water vapor was calculated from Leckner formula. Subscale calorimeter was chosen as the computational model. Results showed that numerical results agreed well with experimental data.The flow field and temperature field in nozzle were obtained.