Accession Number:

ADA076121

Title:

Evolution of Turbulence by Three-Dimensional Numerical Particle-Vortex Tracing,

Descriptive Note:

Corporate Author:

STANFORD UNIV CA INST FOR PLASMA RESEARCH

Personal Author(s):

Report Date:

1979-08-01

Pagination or Media Count:

190.0

Abstract:

A new method for the numerical simulation of three-dimensional incompressible flows is described. Our vortex-in-cell VIC method traces the motion of the vortex filaments in the velocity field which these filaments create. The velocity field is not calculated by creating a mesh-record of the vorticity field, then integrating a Poissons equation via the fast Fourier transform to get the stream function and generating a mesh-record of the velocity field. The computed scales of motion are assumed to be essentially inviscid. Viscous or subgrid-scale effects are incorporated into a filtering procedure in wave vector space. Three computational experiments were pursued in three-dimensional space. The velocity of translation of a single vortex ring was measured and compared with the Biot-Savart law. Next, the evolution in time of an infinite periodic array of closed vortex filaments Taylor-Green was studied. The third simulation follows a mixing layer from an initial state of uniform vorticity with two- and three-dimensional small perturbations. Streamwise perturbations lead to the usual roll-up of vortex patterns with spanwise uniformity.

Subject Categories:

  • Fluid Mechanics
  • Plasma Physics and Magnetohydrodynamics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE