级间通道构型对双脉冲发动机燃烧室局部受热的影响

Effects of Two-Stage Pulse Channel Configurations on Local Heat Transfer Characteristics in Combustion Chamber of Dual Pulse Motor

关键词:  双脉冲发动机  内流场  数值分析

Key words:  Dual pulse motor  Inner flow field  Numerical analysis

摘要:

为研究级间通道构型对双脉冲发动机一脉冲燃烧室气流再附着点的位置和对流换热系数的影响，本文采用基于格心的迎风型有限体积法数值求解雷诺平均Navier-Stokes方程组，空间离散采用AUSM-PW矢通量分裂格式，时间推进采用3阶三步TVD型Runge-Kutta显式方法，湍流模型采用适合模拟分离流动的改进SST湍流模型，并通过经验公式计算再附着点处的对流换热系数。结果表明:亚声速后台阶流动和固体火箭发动机燃烧室内流动的最大绝对误差分别为8.9%和5.8%；二脉冲工作的不同时刻，当二脉冲装药内孔直径大于级间通道直径时，级间孔直径每增大9.1%，气流再附着点位置平均减小28.2%，对流换热系数平均下降9.6%；其它条件相同时，级间孔宽度增加对气流再附着点位置和对流换热的影响比较小；级间孔角度变大使得气流再附着点的位置和对流换热系数分别平均下降3.4%和3.1%。

Abstract:

In order to study the effects of two-stage pulse channel configurations on reattachment location and relative convective heat transfer coefficient in combustion chamber of dual pulse motor，the Reynolds-average Navier-Stokes equations were solved with three-order three-step Runge-Kutta iterative algorithm by cell center upwind finite volume method and AUSM-PW scheme were implemented for spatial discretization. Also，modified SST (shear-stress-transport) turbulence model that improved the capability of predicting separation was used to simulate the turbulence flow. The results show that the maximum absolute error of subsonic flow over backward facing step and solid rocket motor combustion chamber flow are within 8.9% and 5.8%，respectively. During the second pulse phase，when the inner diameter of the second grain larger than the one of the pulse channel，as the diameter of pulse channel increases by 9.1%，the reattachment location and relative convective heat transfer coefficient decrease by an average of 28.2% and 9.6%，respectively. When the other conditions are constant，as the channel angle increases，the reattachment location and relative convective heat transfer coefficient reduce by about 3.4% and 3.1% in average，respectively while the value varies slightly with increasing the pulse channel width.