Previous works for a liquid suddenly contacting a gas at a supercritical pressure show the coexistence of both phases and the generation of diffusion layers on both sides of the liquid-gas interface due to thermodynamic phase equilibrium. A related numerical study of a laminar mixing layer between the liquid and gas streams in the near field of the splitter plate suggests that mass, momentum and thermal diffusion layers evolve in a self-similar manner at very high pressures. In this paper, the high-pressure, two-phase, laminar mixing-layer equations are recast in terms of a similarity variable. A liquid hydrocarbon and gaseous oxygen are considered. Freestream conditions and proper matching conditions at the liquid-gas interface are applied. To solve the system of equations, a real-fluid thermodynamic model based on the Soave-Redlich-Kwong equation of state is selected. A comparison with results obtained by directly solving the laminar mixing-layer equations shows the validity of the similarity approach applied to non-ideal two-phase flows. Even when the gas is hotter than the liquid, condensation can occur at high pressures while heat conducts into the liquid. Finally, a generalized correlation is proposed to represent the evolution of the mixing layer thickness for different problem setups.

中文翻译：

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超临界两相层流混合层的自相似解

先前关于液体在超临界压力下突然接触气体的工作表明，由于热力学相平衡，两相共存并在液-气界面两侧产生扩散层。对分流板近场中液体和气体流之间的层流混合层的相关数值研究表明，质量、动量和热扩散层在非常高的压力下以自相似的方式演变。在本文中，高压、两相、层流混合层方程根据相似变量进行了重构。考虑液态烃和气态氧。在液-气界面应用自由流条件和适当的匹配条件。为了求解方程组，选择了基于 Soave-Redlich-Kwong 状态方程的真实流体热力学模型。与通过直接求解层流混合层方程获得的结果进行比较，表明相似方法适用于非理想两相流的有效性。即使气体比液体热，在高压下也会发生冷凝，同时热量会传导到液体中。最后，提出了一种广义相关性来表示不同问题设置下混合层厚度的演变。