Masters Theses

Date of Award

8-1995

Degree Type

Thesis

Degree Name

Master of Science

Major

Engineering Science

Major Professor

A. J. Baker

Committee Members

G. S. Iannelli, R. D. Krieg

Abstract

A time step control method has been implemented and evaluated for CFD algorithm stability, hence efficiency, via the AKCESS. * software platform which utilizes a "template" and "hook" format for implementing discrete algorithm variations. The time step control method monitors the extremum Newton iterate change in the solution field, at the beginning of each time step, and uses this information on line to adjust the time step size for the next time station. This method has been tested on two benchmark problems (driven cavity and thermal cavity) using weak statement finite element formulations based on vorticity-streamfunction, the continuity constraint (pressure relaxation) method, and the penalty method. A test matrix containing 35 cases is presented, demonstrating the versatility and effectiveness of the time step control method for both implicit and explicit time integration. Overall, the time step controller is a tool that enables a problem to converge to a steady-state solution with minimal user interaction (i.e., frustration) with the computer.

Download
Files over 3MB may be slow to open. For best results, right-click and select "save as..."

Share

COinS