A hybrid computational approach to multiplebody viscousflow problems: Application to largeeddy breakup in a boundary layer
Abstract
A hybrid computational procedure is presented which combines the streamfunction and integralvelocity formulations. It is applicable to unsteady twodimensional flows about multiple bodies. The free vorticity of the fluid is computed by a standard finitedifference procedure, and the bodies within the flow are replaced by distributions of bound vorticity over their surfaces. The bound vorticity prevents fluid penetration at the body surfaces and produces an irrotational velocity field which is evaluated in integral form. The free vorticity produces a rotational velocity field which is expressed in terms of the stream function. In this way, boundary conditions on the stream function are needed only on the periphery of the computational domain. These involve integrals over the known bound and free vorticity fields, and the boundary conditions are thus allowed to change with time and space as the flow evolves. The procedure is used to simulate the breakup of coherent eddies by a single flat plate embedded in a viscous boundary layer. Significant features of the unsteady flow are revealed by graphical presentations of the vorticity contours as well as flow visualization using marker particles.
 Publication:

Journal of Computational Physics
 Pub Date:
 October 1988
 DOI:
 10.1016/00219991(88)900563
 Bibcode:
 1988JCoPh..78..378K
 Keywords:

 Boundary Layer Flow;
 Computational Fluid Dynamics;
 Viscous Flow;
 Vortex Breakdown;
 Boundary Conditions;
 Cascade Flow;
 Finite Difference Theory;
 Flow Visualization;
 Spectral Methods;
 Stream Functions (Fluids);
 Vorticity;
 Fluid Mechanics and Heat Transfer