再生冷却结构参数对煤油流动换热的影响及优化

为揭示冲压发动机燃烧室再生冷却结构参数对煤油流动换热的影响,实现对结构参数的优化,以单根再生冷却通道为研究对象,在通道总数一定的情况下,分别对RP-3航空煤油在不同内壁厚度、肋片厚度及高度的通道中流动换热进行了数值研究,发现薄内壁的通道冷却效果好,流动压力损失稍大;厚肋片的通道冷却效果好,但压力损失随肋片厚度的增大而急剧增大;随着高度增大,冷却效果变差,但流动压力损失急剧减小;3种结构参数对油温的影响都很小。分别对影响机理进行了理论分析,在此基础上,为得到一种对流换热效果尽可能好以及流动压力损失尽可能小的冷却通道,利用Workbench平台的目标驱动优化工具,采用遗传算法对冷却通道进行优化设计,经校验,优化后的通道满足设计目标。

Research on Optimization and the Influence of Regenerative Cooling Structure Parameters on Kerosene Flow and Heat Transfer

In order to reveal the influence of scramjet combustor regenerative cooling structure parameters on flow and heat transfer of aviation kerosene, and realize the optimization of the structure parameters under condition of the fixed total number of cooling channels, this paper researches respectively flow and heat transfer condition of No. 3 aviation kerosene in cooling channel with different inside wall thickness, fin thickness and aspect ratios taking single cooling channel as an object of study. The results show that the cooling effect is improved and the flow pressure loss increases slightly with decrease of the inside wall thickness. The cooling effect is improved and the flow pressure loss increases rapidly with increase of the fin thickness. The cooling effect deteriorates and the flow pressure loss decreases rapidly with increase of height. But the three structure parameters have little effects on the fluid temperature. In addition, the influence mechanism is theoretically analyzed respectively. On this basis, an optimal design of cooling channel is made by goal driven optimization and MOGA in Workbench for the best possible cooling effect and the smallest possible flow pressure loss. The checkout shows that the optimized structure meets the needs of the design pursuit.