[论文解读] Fully Turbulent Wakes at Low Reynolds Numbers: the Case of the Thin Flat Plate

Isaac T. Rosin, Melanie S. Chapman+2 more|arXiv (Cornell University)|Jan 24, 2026

Fluid Dynamics and Vibration Analysis被引用 0

一句话总结

作者通过将 DNS 结果与在更高 Re 的实验进行比较，发现穿过一个薄的二维平板的尾流在相对较低的雷诺数（Re = 400）就变得湍流，揭示了与更高 Re 的尾流在均流和湍流能量传输特征以及能谱方面相似的迹象，与 Re = 150 的尾流不同。

ABSTRACT

We consider the wake flow past a thin two-dimensional flat plate normal to the uniform stream and demonstrate that this flow is turbulent already at a relatively low Reynolds number of $Re = 400$. This is achieved by performing a careful comparison of the results of a DNS of this flow with experimental measurements of wake flows in the same geometric configuration at the Reynolds numbers of $Re=12500, 19700$. This comparison reveals that the distribution of several key quantities, including the mean velocity, Reynolds stresses and different effects contributing to the transport of the turbulent kinetic energy, are, up to measurement uncertainty, the same in these flows. Moreover, the wake flow at $Re = 400$ also features energy spectra characteristic of turbulent flows with intermittency detected in the distributions of the fluctuating strain and rotation rates. In contrast, these features are absent from the results of the DNS of the wake flow at $Re = 150$ where the distribution of the key quantities is also fundamentally different. These results show that the path to transition to turbulence in the wake past a thin flat plate is different from that in the wakes of canonical (i.e., circular or square) cylinders. We also identify possible physical mechanisms that may be responsible for these differences.

研究动机与目标

• 研究一个垂直于均匀流的薄二维平板后方的尾流流动。
• 通过将 DNS 与更高 Re 的实验数据进行比较，评估低雷诺数是否出现湍流特征。
• 确定该几何形状与圆柱/方柱等典型尾流在过渡路径上的差异。
• 识别可能解释观测到的湍化差异的物理机制。

提出的方法

• 对垂直于流的薄平板后方尾流进行 DNS。
• 在相同几何形状下，将 DNS 结果与 Re = 12500 和 Re = 19700 的实验尾流测量结果进行比较。
• 分析平均速度、雷诺应力及湍动能传输项。
• 检验能谱以及在振荡应变率和旋转率中的间歇性。
• 与 Re = 150 的 DNS 结果进行对比，以评估过渡行为。

实验结果

研究问题

• RQ1 薄板后方的尾流在低雷诺数（约 Re = 400）时是否呈现湍流？
• RQ2 DNS 结果与在均场、应力和能量传输方面的高 Re 实验测量结果有何差异？
• RQ3 低 Re 尾流的谱特性与间歇性特征如何，以及它们与湍流的关系？
• RQ4 该几何形状的过渡路径与经典圆柱尾流有何不同，驱动这些差异的机制是什么？

主要发现

• 薄板后方的尾流在 Re = 400 时呈湍流，基于与 Re = 12500 和 19700 的实验对比。
• 在测量不确定性范围内，低 Re 与高 Re 情况下的平均速度、雷诺应力和湍动能传输项保持一致。
• 在 Re = 400 时的能谱显示出类似湍流的特征，且在振荡应变率和旋转率中检测到间歇性。
• 在 Re = 150 的 DNS 结果中，关键量的分布与 Re = 400 的情形根本不同，表明其过渡路径不同。
• 观测到的过渡差异归因于尾流几何形状，提示与经典圆柱尾流不同的物理机制。