Stability diagram and effect of initial density stratification for a two-layer system in a supercritical fluid
Stability diagram and effect of initial density stratification for a two-layer system in a supercritical fluid
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DOI：
10.1063/1.2424497
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发表时间：
2006-12
影响因子：
4.6
通讯作者：
K. Boutrouft;S. Amiroudine;A. Ambari
中科院分区：
文献类型：
--
作者：
K. Boutrouft;S. Amiroudine;A. Ambari
对填充有单一纯超临界流体的两层系统在初始温差下的稳定性进行了数值研究。近临界流体非常大的可压缩性和非常低的热扩散率导致热扩散层出现类似瑞利-泰勒的重力不稳定性。这种不稳定性类似于两种可混溶流体之一，其中分子物质扩散系数被热扩散系数取代。我们的数值结果与 Duff 等人推导出的色散关系一致。 [物理。 Fluids 5, 417 (1962)] 用于两种不可压缩混溶流体的系统（氩溴混合物落入氦气或空气中）。还表明，当下层的厚度变得小于基于最大生长速率的热扩散长度时，系统是稳定的[Phys.流体 17, 054102 (2005)]。线性稳定性图已建立为三个参数的函数：厚...
A numerical study of the stability in a two-layer system filled with a single pure supercritical fluid subjected to an initial temperature difference is performed. The very large compressibility and the very low heat diffusivity of near-critical fluids lead to a Rayleigh-Taylor-like gravitational instability of the heat diffusion layer. This instability is similar to the one of two miscible fluids where molecular species diffusion coefficient is replaced by the heat diffusion coefficient. Our numerical results are consistent with respect to the dispersion relation derived by Duff et al. [Phys. Fluids 5, 417 (1962)] for a system of two incompressible miscible fluids (argon-bromine mixture falling into helium or air). It has also been shown that when the thickness of the lower layer becomes smaller than the heat diffusion length based on the maximum growth rate, the system is stable [Phys. Fluids 17, 054102 (2005)]. A linear stability diagram has been established as a function of three parameters: the thick...