Implicit method for the computation of unsteady flows on unstructured grids

Journal Article · Sun Sep 01 04:00:00 EDT 1996 · Journal of Computational Physics

DOI:https://doi.org/10.1006/jcph.1996.0182· OSTI ID:478589

Venkatakrishnan, V; Mavriplis, D J ^[1]

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1. NASA, Hampton, VA (United States)

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. 48 refs., 24 figs.

• OSTI ID: 478589
• Journal Information: Journal of Computational Physics, Journal Name: Journal of Computational Physics Journal Issue: 2 Vol. 127; ISSN JCTPAH; ISSN 0021-9991
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
66 PHYSICS
99 GENERAL AND MISCELLANEOUS
AIRFOILS
FINITE DIFFERENCE METHOD
FLOW MODELS
MESH GENERATION
UNSTEADY FLOW