肋参数对液氧甲烷发动机推力室强化换热的影响

Effects of Rib Parameters on Heat Transfer Enhancement in Thrust Chambers with LOX/Methane Engine

为深入研究带肋推力室强化传热的机理,对带肋液氧/甲烷推力室的燃烧与再生冷却进行了流动与传热耦合分析,并针对不同肋高和肋数目进行了参数化分析。结果表明:引入等效平均热流密度的概念可以准确描述带肋推力室中的实际传热过程;平均热流密度总是随着肋数目的增加而减小,当肋高恒定时,由于总换热面积增大,等效平均热流密度会随着肋数目的增加而增大;而当总表面积恒定时,等效平均热流密度会随肋数目的增加而减小。此外,盲目地增大总换热面积并不一定能改善传热强化,甚至会在某些情况下恶化传热,因此在设计过程中也应该结合其他肋参数进行综合考虑。

In order to further study the mechanism of heat transfer enhancement in ribbed thrust chambers,the coupled flow and heat transfer of the combustion and regeneration cooling in ribbed LOX/methane thrust chambers are analyzed,and a parametric analysis is carried out for different rib heights and different rib numbers.The results show that the actual heat transfer of ribbed thrust chambers can be accurately described by introducing the concept of equivalent-average heat flux.The average heat flux decreases with the increase in the rib number.At a constant rib height,the equivalent average heat flux increases with the increase in the rib number since the total heat transfer area increases.However,at a constant total surface area,the equivalent-average heat flux decreases with the increase in the rib number.Additionally,increasing the total surface area blindly does not necessarily improve the heat transfer enhancement.In some cases,it can even worsen the heat transfer.Besides,the rib efficiency decreases with the increase in the rib number.Therefore,the design should be comprehensively considered with other rib parameters.