Project Title:

A Fully Conservative Chimera Approach for Structured/Unstructured

CFD Research Corp.
3325 Triana Blvd.
Huntsville, AL 35805

93-1 02.01 6576

A Fully Conservative Chimera Approach for Structured/Unstructured
Grids in Computational Fluid Dynamics

Abstract:

In the field of Computational Fluid Dynamics (CFD), a multi-zonal
approach greatly facilitates adequate representation of complex
geometry and different flow physics in different parts of the
flow domain. Previous multi-zonal patched and overlapped
approaches suffered from one or both of the following problems:
conservation and generality. A new approach is proposed to
resolve both of these problems. In the proposed approach, one of
the overlapping boundaries is used to divide the physical flow
domain into non-overlapping regions and flux conservation is
enforced on this overlapping boundary locally and globally. The
interpolation of flow variables from one zone to another is not
necessary. The proposed approach can handle overlapped structured
and unstructured grids, thus increasing its capability of
handling geometrically very complex components. The proposed
approach is fully conservative, suitable for both steady and
unsteady flow problems and easy to implement in
finite-difference/finite volume CFD codes. In Phase I, the
proposed methodology will be implemented and assessed for
selected 2D and 3D problems without relative mesh movement.
Further extension to viscous flows and unsteady flows with
relative mesh movement and implementation of the proposed 
methodology in a production-level flow analysis code will be  
carried out in Phase II.

The proposed project will provide a general, highly accurate,
fully conservative zonal interface method for arbitrarily aligned
structured/unstructured multi-zonal meshes. The stand alone
modules produced in Phase I can be easily integrated into
multi-zonal CFD codes, greatly enhancing their ability to handle
complex geometries with improved accuracy. The final adapted CFD
code, produced in Phase II, will have wide applications both in
Government and private industry.

Computational Fluid Dynamics, Conservative, Hybrid Grids,
Overlapped Grids, Chimera Scheme