Abstract:

Pressure, temperature, vapor-liquid interface and other parameters of a liquid oxygen tank for long-term storage in orbit are simulated through CFD (computational fluid dynamics) method.The average heat leak of the tank in orbit is calculated, and it is 6.84 W·m^-2.The tank is simulated for 5 days, and the result indicates that the vapor region formed at the top of the tank is unstable, and the temperature of the liquid region is uniform as the thermal stratification is weakened by the high-speed vapor mass inside the liquid region.During the storage process in orbit, the temperature increase rate of the liquid is 1.18 K·d^-1, and the pressure increase rate of the tank is 23.7 kPa·d^-1.According to the flow field inside the tank, the homogeneous model is established, and results calculated by the model are coincided with the CFD method.Therefore, the homogeneous model is favorable for the prediction of pressure, evaporation and other parameters in the cryogenic propellant tank for long-term storage in orbit.

Key words: liquid oxygen, tank, heat transfer, vaporization, phase change, microgravity, numerical simulation

摘要：

通过CFD（computational fluid dynamics）方法对长期在轨运行的某型液氧贮箱内的压力、温度、气液相界面等参数进行了模拟研究。计算了该型贮箱在轨运行时的平均漏热量为6.84 W·m^-2。对贮箱进行了5天的模拟计算，结果表明，贮箱上部的气枕区并不稳定；液相区存在相对高速运动的气团，削弱了液相区的温度分层，使得液相区温度基本均匀。在轨储存过程中，液相温升速率为1.18 K·d^-1，压增速率为23.7 kPa·d^-1。结合贮箱内气液相运动特点，建立均相模型，该模型与CFD模拟结果吻合较好，可以用来预测长期在轨运行的低温推进剂贮箱内的压力、蒸发量等参数变化。

关键词: 液氧, 贮箱, 传热, 汽化, 相变, 微重力, 数值模拟