
Accession Number : ADA182391
Title : A Fast Algorithm for NonNewtonian Flow.
Descriptive Note : Annual technical rept., Apr 86Mar 87,
Corporate Author : WISCONSIN UNIVMADISON 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