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围绕一个动荡区域的旋转运动的一般化缩放规律
Marco Zecchetto1, Ricardo P Xavier1, Miguel A C Teixeira2
1IDMEC/LAETA, Instituto Superior Técnico, <a href="https://ror.org/01c27hj86">Universidade de Lisboa</a>, 1049-001 Lisboa, Portugal.
Physical review. E
|July 18, 2024
概括
我们推导出了流-非流接口附近潜在速度波动的新的缩放规律. 这些定律是基于动能光谱的.
科学领域:
- 流体动力学 流体动力学
- 流理论 流理论
- 计算物理 计算物理
背景情况:
- 动荡的自由剪流和边界层在动荡-非动荡接口层 (TNTI) 附近表现出高潜在的速度波动.
- 之前的研究建立了远离TNTI (x2 ≫ L) 的速度波动变异 (ui2) 的缩放规律,基于动能光谱的红外区域 (E(k) ∼kn).
- 像巴切勒 (n=4) 和萨夫曼 (n=2) 流这样的特定情况具有已知的缩放规律 (分别为ui2∼x2−4和ui2∼x2−3).
研究的目的:
- 在与流相邻的无旋流流域中对潜在速度波动的缩放规律进行概括.
- 扩展现有理论,涵盖动能光谱的红外区域中的任何光谱指数'n'.
- 通过直接的数值模拟来验证理论预测.
主要方法:
- 快速扭曲理论的应用,以导出通用化的缩放规律.
- 对动能光谱的红外区域 (E(k) ~kn) 的分析.
- 直接的数值模拟流前线与旋转流相互作用.
主要成果:
- 导出了潜在速度波动 (ui2) 的一般化缩放定律,作为距离TNTI (x2) 的函数.
- 获得了新的缩放定律:ui2∼x2−2为n=1,ui2∼x2−4为n≥5.5.
- 发现n=3产生ui2∼x2−4ln(x2),扩展了n=2和n=4.4的先前发现.
结论:
- 衍生出的通用缩放定律准确地描述了各种动能频谱形状的潜在速度波动.
- 理论预测通过直接的数值模拟得到了强有力的证实.
- 这项工作提供了一个全面的理解流动动力学在动-非动接口.
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