论文标题
粘性涡流重新连接的分离缩放
Separation scaling for viscous vortex reconnection
论文作者
论文摘要
重新连接在等离子体，聚合物和大分子的动力学以及经典和量子流体的许多层流和湍流现象中起着重要作用。量子涡流重新连接的广泛研究表明，相互作用涡流之间的最小分离距离δ遵循1/2缩放。由于动力学的复杂性（例如，桥梁和线的形成以及连续的重新连接和雪崩），从未报道过这种缩放的（经典）粘性涡旋重新连接。使用Navier-Stokes方程的直接数值模拟，我们研究了细长涡流的粘性重新连接，其核心大小远小于涡旋曲率的半径。对于与涡旋核心大小相比，分离较大的分离，我们发现两个相互作用的粘性涡旋之间的δ（t）出人意料地遵循了回归事件前后的1/2功率缩放。发现该1/2-Power定律中的预成分不仅取决于初始配置，还取决于涡旋雷诺数（或粘度）。我们在粘性重新连接中的发现，补充了量子涡流重新连接的众多作品，这确实存在着重新连接的普遍途径 - 了解粘性涡流重新连接现象的各个方面及其潜在的建模及其潜在的建模，以及可能解释湍流级联物理学。
Reconnection plays a significant role in the dynamics of plasmas, polymers and macromolecules, as well as in numerous laminar and turbulent flow phenomena in both classical and quantum fluids. Extensive studies in quantum vortex reconnection show that the minimum separation distance δ between interacting vortices follows a 1/2 scaling. Due to the complex nature of the dynamics (e.g., the formation of bridges and threads as well as successive reconnections and avalanche), such scaling has never been reported for (classical) viscous vortex reconnection. Using the direct numerical simulation of the Navier-Stokes equations, we study viscous reconnection of slender vortices, whose core size is much smaller than the radius of the vortex curvature. For separations that are large compared to the vortex core size, we discover that δ(t) between the two interacting viscous vortices surprisingly also follows the 1/2 power scaling for both pre- and post-reconnection events. The prefactors in this 1/2-power law are found to depend not only on the initial configuration but also on the vortex Reynolds number (or viscosity). Our finding in the viscous reconnection, complementing numerous works on quantum vortex reconnection, suggests that there is indeed a universal route for reconnection -- an essential result for understanding the various facets of the viscous vortex reconnection phenomena and their potential modeling, as well as possibly explaining turbulence cascade physics.
