Accession Number : ADA299899

Title :   Implicit Method for the Computation of Unsteady Flows on Unstructured Grids.

Descriptive Note : Contract rept.,

Corporate Author : INSTITUTE FOR COMPUTER APPLICATIONS IN SCIENCE AND ENGINEERING HAMPTON VA

Personal Author(s) : Venkatakrishnan, V. ; Mavriplis, D. J.

PDF Url : ADA299899

Report Date : AUG 1995

Pagination or Media Count : 36

Abstract : An implicit method for the computation of unsteady flows on unstructured grids is presented. Following a finite difference approximation for the time derivative, the resulting nonlinear system of equations is solved at each time step by using an agglomeration multigrid procedure. The method allows for arbitrarily large time steps and is efficient in terms of computational effort and storage. Inviscid and viscous unsteady flows are computed to validate the procedure. The issue of the mass matrix which arises with vertex-centered finite volume schemes is addressed. The present formulation allows the mass matrix to be inverted indirectly. A mesh point movement and reconnection procedure is described that allows the grids to evolve with the motion of bodies. As an example of flow over bodies in relative motion, flow over a multi-element airfoil system undergoing deployment is computed.

Descriptors :   *COMPUTATIONS, *GRIDS, *UNSTEADY FLOW, MOTION, AIRFOILS, MESH, TIME, FINITE DIFFERENCE THEORY, APPROXIMATION(MATHEMATICS), FLOW, STORAGE, EQUATIONS, INVISCID FLOW, VISCOUS FLOW, NONLINEAR ALGEBRAIC EQUATIONS.

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE