Numerical simulation of three-dimensional trailing vortex evolution in stratified fluid
Numerical simulation of three-dimensional trailing vortex evolution in stratified fluid
复制标题
分层流体三维尾随涡演化的数值模拟
作者：
R. Robins;D. Delisi
纳维-斯托克斯方程的数值解描述了在分层、不可压缩流体中下降的尾涡对的演化。显示了弗劳德数 1、2、4、8 和无穷大的三维和二维结果。对于三维和二维，结果表明，分层通过产生副号涡量，导致涡流之间的分离减小，并通过浮力抑制涡流的垂直迁移。在三维空间中，当弗劳德数大于或等于 4 时，克劳不稳定性会导致涡流最终连接并形成环，并且分层越高（弗劳德数越低），连接和环形成发生的速率就越大。
Numerical solutions to the Navier-Stokes equations that depict the evolution of a trailing vortex pair descending in stratified, incompressible fluid are presented. Both three-dimensional and two-dimensional results are shown for the Froude numbers 1, 2, 4, and 8 and infinity. For three and two dimensions, the results indicate that stratification, through generation of countersign vorticity, causes the separation between the vortices to decrease and, through buoyancy forces, suppresses the vertical migration of the vortices. In three dimensions, Crow instability causes the vortices eventually to link and to form rings when the Froude number is greater than or equal to 4, and the rate at which the linking and ring formation occur is greater for higher stratification (lower Froude number)