Three-dimensional simulation of the free shear layer using the vortex-in-cell methodWe present numerical simulations of the evolution of a mixing layer from an initial state of uniform vorticity with simple two- and three-dimensional small perturbations. A new method for tracing a large number of three-dimensional vortex filaments is used in the simulations. Vortex tracing by Biot-Savart interaction originally implied ideal (non-viscous) flow, but we use a 3-d mesh, Fourier transforms and filtering for vortex tracing, which implies 'modeling' of subgrid scale motion and hence some viscosity. Streamwise perturbations lead to the usual roll-up of vortex patterns with spanwise uniformity maintained. Remarkably, spanwise perturbations generate streamwise distortions of the vortex filaments and the combination of both perturbations leads to patterns with interesting features discernable in the movies and in the records of enstrophy and energy for the three components of the flow.
Document ID
19800065130
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Couet, B. (Stanford Univ. CA, United States)
Buneman, O. (Stanford University Stanford, Calif., United States)
Leonard, A. (NASA Ames Research Center Moffett Field, Calif., United States)