旋转固体火箭发动机喷管热结构分析

以某固体火箭发动机喷管为例,研究其旋转情况下的流动、传热及热结构响应性能。利用雷诺应力湍流模型,结合增强型壁面函数,求解N-S方程。以喷管内壁面温度分布为边界条件,求解二维轴对称瞬态热传导方程。将瞬态温度场按时间步长加载,进行瞬态静力学分析,得到不同转速下的流场、温度场及应力场。结果表明,喷管在旋转情况下,喷管内壁面尤其是喉部及扩张段温度分布在转速为100 r/min及600 r/min左右时变化剧烈;旋转内流场与喷管结构的耦合作用加剧了喷管的传热,尤其是喉衬的烧蚀,特征点温度值随转速增大而升高;最大热应力位于喷管最外层尾端,整体热应力在转速低于100 r/min时得到释放,随着转速的不断增大,喷管整体最大热应力及扩张段特征点应力随之增大,而喉衬特征点由于旋转导致了温度梯度降低,其应力值随之减小。

Thermo-Structural Analysis of Spinning SRM Nozzle

A numerical study on a solid rocket motor nozzle is conducted to analyze the flow ,heat transfer and thermo-structure performance .Reynolds Stress viscous model and enhanced wall function are used to solve Navier-Stokes equations .By setting the inner wall temperature distribution as boundary condition , the two-dimensional axisymmetric transient heat transfer equation is solved .By loading the temperature field by step time , a transient static structure analysis is proposed .The flow field , temperature field and stress field are obtained .The results show that for this nozzle ,spinning lead to a severe change in inner wall temperature distribution especially at nozzle insert and the divergent section when speed is 100 r/min and 600 r/min.A coupled effect of spinning flow field and structure results in severe heat transfer especially erosion of nozzle insert .The temperature of the characteristic points increases along with the spinning speed .The maximum Von-Mises stress is at end of the outermost .The entire stress can released when spinning speed is lower than 100 r/min.The maximum Von-Mises stress of the nozzle and the characteristic point at divergent section increases with the spinning speed , while the characteristic point at nozzle insert decreases because of temperature gradient decreasing leading by spinning .