液氢和液氮绕水翼空化流动特性分析

摘要

The objective of this study is to analyze the cavitation characteristics in liquid hydrogen and nitrogen. The aim was realized by implanting the Schnerr⁃Sauer cavitation model and the physical properties of liquid hydrogen and liquid nitrogen at different temperatures into the CFX solver code, and coupling the energy equation considering the latent heat. Then the three⁃dimensional numerical simulation of cavitating flows was conducted around a hydrofoil in liquid hydrogen and nitrogen, and the experimental results of the pressure and temperature were utilized to validate the numerical strategy. The results show that the thermodynamic effects have more pronounced impact on the pressure and temperature in the cavitation region of liquid hydrogen. The liquid phase volume fraction in liquid nitrogen is smaller in the core cavitation region than that of liquid hydrogen,and the rate of phase transition from vapor to liquid is large in the closure region. The mass transfer rate between liquid and vapor can be used to evaluate the temperature, pressure and phase volume fraction inside the cavity effectively.%为分析液氢和液氮两种低温流体介质的空化特性，通过对CFX软件二次开发，将Schnerr⁃Sauer空化模型和液氮、液氢随温度变化的物性参数嵌入到CFX求解代码中，同时耦合求解考虑汽化潜热影响的能量方程，从而在考虑热力学效应条件下，开展了液氢和液氮绕水翼空化流动的三维数值模拟研究，并将计算结果与试验数据进行对比，验证了数值方法的有效性。计算结果表明，热力学效应对液氢空化区域压力和温度参数变化影响更显著，在液氮空化核心区域内液相体积分数比液氢中的更小，在空泡尾部闭合区域从汽相向液相转化迅速。汽－液两相间质量传输特性可作为评估空化区域内温度、压力以及相体积分数分布的有效依据。