贮箱内低温推进剂汽化过程的CFD数值仿真

为研究贮箱内低温推进剂相变对推进剂温度和贮箱压力的影响,对贮箱内的传热传质过程进行了仿真.仿真涉及的物理过程包括贮箱与外界环境的换热、推进剂的自然对流、推进剂与贮箱内壁面的换热以及低温推进剂的相变过程等.根据热力学平衡原理建立了低温推进剂相变模型,使用CFD(Computational Fluid Dynamic)方法对处于地面常压停放状态的液氢贮箱进行了450 s的仿真.研究表明随着贮箱壁面传热过程的稳定,推进剂的温度分布、流动状态以及相变情况会趋于稳定;通过仿真获得了推进剂单位时间的汽化量;影响相变的主要因素是贮箱壁面漏热以及推进剂自身的对流运动.

CFD numerical simulation of cryogenic propellant vaporization in tank

Simulation on heat and mass transfer in propellant tank was performed to investigate influence of cryogenic propellant vaporization on tank pressure and propellant temperature. The simulation was concerned with heat transfer between propellant tank and external environment, propellant free convection, thermal exchange between propellant and inner tank wall surface, and cryogenic propellant phase transition. A propellant phase transformation model was built on the basis of thermodynamic equilibrium. Physical process of 450s in propellant tank during ground parking under atmospheric pressure was simulated using computational fluid dynamic(CFD) method. Simulation results reveal that the propellant temperature distribution, flow state and phase transition will tend to stable as propellant tank wall heat transfer stabilizes. The evaporation of propellant per unit time was obtained through simulation. And the main factors affecting the propellant phase transition are heat leak from tank walls and the propellant's own convection motion.