Accession Number : ADA182391

Title :   A Fast Algorithm for Non-Newtonian Flow.

Descriptive Note : Annual technical rept., Apr 86-Mar 87,

Corporate Author : WISCONSIN UNIV-MADISON DEPT OF ENGINEERING MECHANICS

Personal Author(s) : Malkus,David S

PDF Url : ADA182391

Report Date : 30 Apr 1987

Pagination or Media Count : 8

Abstract : The project involves the development of efficient and robust finite element scheme for the solution of fluid flow problems in which the stresses are given by an integral constitutive equation. Improvement is made on the computational efficiency of the stress calculator, which is the heart of the method. First, a simple adaptive memory quadrature scheme has been implemented; second, the code has been vectorized and tested in vector processing environments; third, the code has been streamlined by using local array storage instead of regeneration of elemental quantities. The improvements lead to a factor of two reduction in running time in the most favorable case tested and to a 40% reduction in the least favorable case, with scalar processing. In vector processing an additional 11% reduction in CPU time is observed. Progress has been made in the understanding of convergence difficulties at high Weissenberg numbers by analysis of a simple model problem and its discretization. New aspects of the mathematical nature of simple flows of viscoelastic fluids near and beyond the unsteady transition have been observed.

Descriptors :   *FLUID FLOW, *NONNEWTONIAN FLUIDS, ARRAYS, COMPUTATIONS, EFFICIENCY, FINITE ELEMENT ANALYSIS, FLOW, ALGORITHMS, PROCESSING, SCALAR FUNCTIONS, STRESSES, TIME, VECTOR ANALYSIS, VISCOELASTICITY, ANISOTROPY

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE