Mach Independence of Entropy Layer Instabilities

IF 2.8 3区工程技术 Q2 MECHANICS

Theoretical and Computational Fluid Dynamics Pub Date : 2025-09-17 DOI:10.1007/s00162-025-00758-w

Iliya Milman, Michael Karp

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Abstract

The entropy layer in a hypersonic flow over a blunted body is investigated using a high-accuracy spectral shock-fitting algorithm that solves the Euler equations within the shock layer. The base flow is computed via a direct numerical solution of the nonlinear equations. The analysis pays particular attention to the physical phenomena that arise at geometric discontinuities in body curvature. The flow field around a blunted 30-degree half-angle wedge, used as a representative body, is examined in detail and compared to viscous direct numerical solutions to evaluate the effect of viscosity on the profile of the entropy layer. Instabilities associated with the generalized inflection point in the entropy layer are investigated using linear stability theory. The entropy layer instabilities are shown to exhibit Mach number independence under a proper normalization. Our findings may be particularly useful for relating experimental results at different Mach numbers where the cold flow (calorically perfect gas) assumption is applicable.

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熵层不稳定性的马赫独立性

采用高精度谱激波拟合算法求解激波层内的欧拉方程，研究了钝化体上高超声速流动中的熵层。基流是通过非线性方程的直接数值解来计算的。该分析特别注意在身体曲率的几何不连续处产生的物理现象。以30度半角钝楔为代表体，对其流场进行了详细的研究，并与粘性直接数值解进行了比较，以评价粘性对熵层剖面的影响。利用线性稳定性理论研究了与熵层广义拐点相关的不稳定性。在适当的归一化下，熵层不稳定性表现出与马赫数无关。我们的发现对于不同马赫数下适用冷流（热量完美气体）假设的相关实验结果可能特别有用。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Theoretical and Computational Fluid Dynamics 物理-力学

CiteScore

5.80

自引率

2.90%

发文量

审稿时长

>12 weeks

期刊介绍： Theoretical and Computational Fluid Dynamics provides a forum for the cross fertilization of ideas, tools and techniques across all disciplines in which fluid flow plays a role. The focus is on aspects of fluid dynamics where theory and computation are used to provide insights and data upon which solid physical understanding is revealed. We seek research papers, invited review articles, brief communications, letters and comments addressing flow phenomena of relevance to aeronautical, geophysical, environmental, material, mechanical and life sciences. Papers of a purely algorithmic, experimental or engineering application nature, and papers without significant new physical insights, are outside the scope of this journal. For computational work, authors are responsible for ensuring that any artifacts of discretization and/or implementation are sufficiently controlled such that the numerical results unambiguously support the conclusions drawn. Where appropriate, and to the extent possible, such papers should either include or reference supporting documentation in the form of verification and validation studies.