摘要
针对火箭发动机的再生循环冷却过程,研究了超临界压力下碳氢燃料在圆形和矩形冷却通道内的流动和传热特性。采用RNGk-ε湍流模型结合增强壁面处理方法,通过数值模拟分析了在非对称受热(上壁面加热)情况下流体的速度场、温度场,考察了由传热恶化和热传导共同作用引起的热流异常传递,并得到了两种冷却通道内流体的速度、温度、对流换热系数以及Nusselt数的变化规律。结果发现,近壁面流体率先达到拟临界温度,流体物性参数剧烈变化出现零速度梯度区,导致了传热恶化和“M”形速度等值线;超临界压力下,在z> 280 mm后圆形冷却通道的冷却效果优于矩形。
The flow and heat transfer characteristics of hydrocarbon fuels in circular and rectangular cooling channels at supercritical pressure are investigated for the regenerative cycle cooling process of rocket engines. The velocity and temperature fields of the fluid under asymmetric heating(upper wall heating) are analyzed by numerical simulation using the RNGk-εturbulence model combined with enhanced wall treatment, focusing on the abnormal thermal flux transfer phenomenon caused by the joint effects of heat transfer deterioration and heat conduction. And the variation curves of velocity, temperature, convective heat transfer coefficient and the Nusselt number of the fluid in the two cooling channels are obtained. The results show that the near-wall fluid first reaches the pseudo-critical temperature, and the drastic change of fluid physical parameters leads to the zero-velocity gradient region, which leads to the deterioration of heat transfer and the‘M’-shaped velocity contour. At supercritical pressure, the cooling performance of the circular cooling channel is superior to the rectangular one afterz> 280 mm.
作者
赵金辉
孔清杰
魏延龙
布一凡
Zhao Jinhui;Kong Qingjie;Wei Yanlong;Bu Yifan(School of Mechanical and Power Engineering,Zhengzhou University,Zhengzhou 450000,China)
出处
《低温工程》
CAS
CSCD
北大核心
2023年第1期50-56,共7页
Cryogenics
关键词
超临界
碳氢燃料
传热恶化
对流传热
数值模拟
supercritical
hydrocarbon fuel
heat transfer deterioration
heat convection
numerical simulation
