A Particle Method and Adaptive Treecodefor Vortex Sheet Motion inThree-Dimensional Flow
نویسندگان
چکیده
A particle method is presented for computing vortex sheet motion in three-dimensional flow. The particles representing the sheet are advected by a regularized Biot– Savart integral in which the exact singular kernel is replaced by the Rosenhead– Moore kernel. New particles are inserted to maintain resolution as the sheet rolls up. The particle velocities are evaluated by an adaptive treecode algorithm based on Taylor approximation in Cartesian coordinates, and the necessary Taylor coefficients are computed by a recurrence relation. The adaptive features include a divide-andconquer evaluation strategy, nonuniform rectangular clusters, variable-order approximation, and a run-time choice between Taylor approximation and direct summation. Tests are performed to document the treecode’s accuracy and efficiency. The method is applied to simulate the roll-up of a circular-disk vortex sheet into a vortex ring. Two examples are presented, azimuthal waves on a vortex ring and the merger of two vortex rings. c © 2001 Academic Press
منابع مشابه
Adaptive Panel Representation for 3D Vortex Ring Motion and Instability
A hierarchical panel method for representing vortex sheet surface motion in 3D flow is presented. Unlike previously employed filament methods, each panel is a leaf of the tree, so it can be subdivided locally, which allows an efficient adaptive point insertion. In addition, we developed curvature-based insertion criteria which allow to localize point insertion to the most complicated curved reg...
متن کاملA Localized Approximation Method for Vortical Flows
An approximation method of Moore for Kelvin-Helmholtz instability is formulated as a general method for two-dimensional, incompressible, inviscid flows generated by a vortex sheet. In this method the nonlocal equations describing evolution of the sheet are approximated by a system of (local) differential equations. These equations are useful for predicting singularity formation on the sheet and...
متن کاملEffects of Brownian motion and Thermophoresis on MHD Mixed Convection Stagnation-point Flow of a Nanofluid Toward a Stretching Vertical Sheet in Porous Medium
This article deals with the study of the two-dimensional mixed convection magnetohydrodynamic (MHD) boundary layer of stagnation-point flow over a stretching vertical plate in porous medium filled with a nanofluid. The model used for the nanofluid incorporates the effects of Brownian motion and thermophoresis in the presence of thermal radiation. The skin-friction coefficient, Nusselt number an...
متن کاملThree-Dimensional Boundary Layer Flow and Heat Transfer of a Dusty Fluid Towards a Stretching Sheet with Convective Boundary Conditions
The steady three-dimensional boundary layer flow and heat transfer of a dusty fluid towards a stretching sheet with convective boundary conditions is investigated by using similarity solution approach. The free stream along z-direction impinges on the stretching sheet to produce a flow with different velocity components. The governing equations are reduced into ordinary differential equations b...
متن کاملA dilating vortex particle method for compressible flow ∗
Vortex methods have become useful tools for the computation of incompressible fluid flow. In this work, a vortex particle method for the simulation of unsteady two-dimensional compressible flow is developed. By decomposing the velocity into irrotational and solenoidal parts, and using particles that are able to change volume and that carry vorticity, dilatation, enthalpy, entropy and density, t...
متن کامل