Accession Number : ADA191086

Title :   Efficient, High Resolution Computations of Projectile and Missile Flow Fields.

Descriptive Note : Final rept. 15 Mar 84-14 Sep 87,

Corporate Author : PEDA CORP PALO ALTO CA

Personal Author(s) : Lombard, C K ; Bardina, Jorge ; Luh, R C ; Venkatapathy, Ethiraj

PDF Url : ADA191086

Report Date : Dec 1987

Pagination or Media Count : 33

Abstract : A new family of computational tools is explored in the context of generic problems of interest to Army Research and Development missions. The problems are the SOCBT projectile flow and the MICOM model tactical base flow. Both problems, for which experimental data is available for comparison, have also been extensively computed by other groups with other methods, principally the central difference method of Beam and Warning. Here the techniques we employ and to some extent refine are composite and overset patched mesh systems generated with a new multistep, graphics interactive algebraic procedure FASTWO and the CSCMS symmetric Gauss-Seidel relaxation procedure. The grid generation technique permits comparatively simple direct user control of mesh spacing and quality. The CSCM-S algorithm is an alternating direction space marching method of lines in 2-D and planes in 3-D. The method is economical both in storage and data handling and, also, is rapidly convergent as the result of improved propagation of nonlinear advection, boundary to boundary. In the SOCBT problem the method exhibited convergence in order 100 global iterations and showed improved accuracy vis a vis central difference methods in capturing features of the flow such as shocks and expansions. The method is stable in both elliptic regions and zones of streamwise separated flow including base flow. In the MICOM base flow problem effects of mesh topology and resolution were elucidated.

Descriptors :   *COMPUTATIONS, *FLOW FIELDS, ACCURACY, BASE FLOW, BOUNDARIES, FINITE DIFFERENCE THEORY, DATA PROCESSING, ELLIPSES, ALGEBRA, GRAPHICS, ARMY RESEARCH, EFFICIENCY, HIGH RESOLUTION, EXPERIMENTAL DATA, GRIDS, NAVIER STOKES EQUATIONS, INTERACTIONS, MESH, TOPOLOGY, MODELS, ADVECTION, NONLINEAR SYSTEMS, PROPAGATION, STORAGE, FLOW, GUIDED MISSILES, PROJECTILES, USER NEEDS, FLOW SEPARATION

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE