超越一个古老的冲击波推测,改进纳维尔-斯托克斯的推测
Brad Lee Holian1, Michel Mareschal2, Ramon Ravelo1,3
1Theoretical Division, <a href="https://ror.org/01e41cf67">Los Alamos National Laboratory</a>, Los Alamos, New Mexico 87545, USA.
Physical review. E
|August 20, 2024
概括
这项研究通过结合伯内特非线性和非平衡麦克斯韦放松来增强冲击波的连续理论. 这种方法准确地模拟了各种冲击强度和流体类型的不平衡分子动力学模拟.
科学领域:
- 计算物理 计算物理
- 流体动力学 流体动力学
- 统计力学 统计力学
背景情况:
- 像纳维埃-斯托克斯-福里埃 (NSF) 等连续理论由于局部热力学平衡 (LTE) 的局限性而难以建模强冲击波.
- 无平衡分子动力学 (NEMD) 模拟揭示了与NSF预测偏离的详细冲击波形状,特别是在高梯度下.
研究的目的:
- 通过结合伯内特非线性和非平衡效应,为冲击波形状开发更准确的连续理论.
- 改进在密集流体和稀释气体中的弱和强冲击波的建模.
主要方法:
- 将伯内特非线性纳入LTE连续理论.
- 将麦克斯韦放松直接应用于水力动力学变量,超越基于梯度的放松.
- 将理论预测与冲击波形状的NEMD模拟数据进行比较.
主要成果:
- 增强的连续理论与伯内特非线性成功地复制了在NEMD模拟中观察到的初始冲击上升和斜率,无论是弱冲击还是强冲击.
- 霍利安的猜想虽然包括了伯内特的非线性,但未能捕捉到后冲击放松动态.
- 对水力动力学变量应用的非LTE麦克斯韦放松对于准确建模整个冲击波形状,特别是缓慢恢复平衡至关重要.
结论:
- 伯内特非线性对于准确描述连续理论中的冲击阵线至关重要.
- 标准的LTE连续理论,包括霍利安的猜想,对于模拟完整的冲击波放松过程是不够的.
- 非平衡的麦克斯韦放松是实现连续理论与冲击波NEMD模拟之间完全一致的关键.
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