论文标题
细长的身体的高度唤醒和密度分层的影响
The high-Re far wake of a slender body and the effects of density stratification
论文作者
论文摘要
使用混合模拟研究了带有湍流边界层的细长体的高元素唤醒。尾流生成器是一个6：1 pr齐的球体，基于直径$ d $的雷诺数为$ re = 10^5 $。通过寻找第一次进入细长的身体唤醒的远处，研究了未分层的唤醒到完全自相似的状态。与虚张声势的唤醒不同，这里的流程不受近唤醒中的涡流脱落的主导。取而代之的是，再循环区域很小，近唤醒是准平行的，其特征是存在宽带湍流。模拟表明，这些特殊性改变了尾流的衰减速率，并挑战了普遍性的概念 - 这种想法远离身体，所有动荡的唤醒都以相同的速度衰减。还以Froude数字$ fr = u_ \ infty/nd = 2 $和$ 10 $研究了分层的影响。结果表明，浮力效应的发作取决于尾流生成器，并且远处尾流留住了初始条件的信息。
The high-Reynolds-number wake of a slender body with a turbulent boundary layer is investigated using a hybrid simulation. The wake generator is a 6:1 prolate spheroid and the Reynolds number based on the diameter $D$ is $Re = 10^5$. The transition of the unstratified wake to a state of complete self-similarity is investigated by looking for the first time into the far field of a slender body wake. Unlike bluff-body wakes, here the flow is not dominated by vortex shedding in the near wake. Instead, the recirculation region is very small, the near wake is quasi-parallel and is characterized by the presence of broadband turbulence. The simulations show that these particularities alter the decay rate of the wake significantly and challenge the notion of universality -- the idea that far from the body all turbulent wakes decay at the same rate. The influence of stratification in the wake is also studied at Froude numbers $Fr=U_\infty/ND=2$ and $10$. The results imply that the onset of buoyancy effects depends on the wake generator and that the far wake retains information of the initial conditions.
