论文标题
涡流结构在具有和不稳定分层的流动中的腹膜和标量传输的作用
Role of vortical structures for enstrophy and scalar transport in flows with and without stable stratification
论文作者
论文摘要
在本文中，我们研究了与客观的欧拉相干结构（OECSS）有关的腹膜动力学及其对湍流/非腐烂界面（TNTI）附近的腹部和标量转运的影响，并在没有稳定分层的情况下进行。我们确认，涡流拉伸会在OECS的边界内产生腹膜，而粘性扩散会在结构的边界上转移腹膜。尽管在文献中经常被忽略，但涡旋结构边界内的腹膜粘性很重要。相反，对于此处还研究了弱分层的流动，斜压扭矩的效果可以忽略不计。我们提供的证据表明，OECS会超过被动/主动标量，并通过分子扩散重新分布。最后，我们使用条件分析表明，TNTI跨TNTI的Enstrophy和标量传输方程项的典型曲线与位于湍流Sblayer和湍流核心区域之间边缘的OECS的存在兼容。我们表明，当这些轮廓进一步以OECS的形式进行调节时，它们的大小要高得多。
In this paper, we investigate the enstrophy dynamics in relation to objective Eulerian coherent structures (OECSs) and their impact on the enstrophy and scalar transport near the turbulent/non-turbulent interface (TNTI) in flows with and without stable stratification. We confirm that vortex-stretching produces enstrophy inside the boundaries of the OECSs, while viscous diffusion transfers the enstrophy across the boundaries of the structures. Although often overlooked in the literature, viscous dissipation of enstrophy within the boundaries of vortical structures is significant. Conversely, for the weakly stratified flows also investigated here, the effect of the baroclinic torque is negligible. We provide evidence that the OECSs advect the passive/active scalar and redistribute it via molecular diffusion. Finally, we use conditional analysis to show that the typical profiles of the enstrophy and scalar transport equation terms across the TNTI are compatible with the presence of OECSs positioned at the edge between the turbulent sublayer and the turbulent core region. We show that when these profiles are further conditioned to the presence of OECSs, their magnitude is considerably higher.
