Vortex crystals from 2D Euler flow: Experiment and simulation

Autor: Daniel H. E. Dubin, D. A. Schecter, C. F. Driscoll, K. S. Fine
Rok vydání: 1999
Předmět:
Zdroj: Physics of Fluids. 11:905-914
ISSN: 1089-7666
1070-6631
DOI: 10.1063/1.869961
Popis: Vortex-in-cell simulations that numerically integrate the 2D Euler equations are compared directly to experiments on magnetized electron columns [K. S. Fine, A. C. Cass, W. G. Flynn, and C. F. Driscoll, “Relaxation of 2D turbulence to vortex crystals,” Phys. Rev. Lett. 75, 3277 (1995)], where turbulent flows relax to metastable vortex crystals. A vortex crystal is a lattice of intense small diameter vortices that rotates rigidly in a lower vorticity background. The simulations and experiments relax at the same rates to vortex crystals with similar vorticity distributions. The relaxation is caused by mixing of the background by the intense vortices: the relaxation rate is peaked when the background circulation is 0.2–0.4 times the total circulation. Close quantitative agreement between experiment and simulation provides strong evidence that vortex crystals can be explained without incorporating physics beyond 2D Euler theory, despite small differences between a magnetized electron column and an ideal 2D fluid.
Databáze: OpenAIRE