论文标题
湍流中涡流的滴滴的变形
Deformation of drops by outer eddies in turbulence
论文作者
论文摘要
这里研究了流体流中的滴剂变形，作为流体动能与滴的表面能之间的交换。我们在分析上表明，这种能量交换仅由液压表面的拉伸（或压缩）通过量张量张量来控制。该机制类似于湍流中涡度场的拉伸。利用湍流动力学的非本地性质，我们引入了一种新的分解，该分解从湍流波动的非本地作用中分离出由于局部下降引起的表面效应而产生的能量交换。我们对各向同性湍流中的单次惯性下降进行直接数值模拟，并表明对表面能量的增量的重要贡献是由远离落下表面（外部涡流）的涡流界面的非局部伸展而产生的。我们报告说，这种机制是主导的，并且独立于表面动力学，在一系列韦伯的数字中发生了掉落。这些发现为湍流中的滴剂变形和分解提供了新的灯光，并为改进和简化分手模型打开了场地。
Drop deformation in fluid flows is investigated here as an exchange between the kinetic energy of the fluid and the surface energy of the drop. We show analytically that this energetic exchange is controlled only by the stretching (or compression) of the drop surface by the rate-of-strain tensor. This mechanism is analogous to the stretching of the vorticity field in turbulence. Leveraging the non-local nature of turbulence dynamics, we introduce a new decomposition that isolates the energetic exchange due to local drop-induced surface effects, from the non-local action of turbulent fluctuations. We perform direct numerical simulations of single inertial drops in isotropic turbulence and show that an important contribution to the increments of the surface energy arises from the non-local stretching of the fluid-fluid interface by eddies far from the drop surface (outer eddies). We report that this mechanism is dominant and independent of surface dynamics in a range of Weber numbers in which drop breakup occurs. These findings shed new light on drop deformation and breakup in turbulent flows, and open the venue for the improvement and simplification of breakup models.
