AMOR

 

Elimination AD Applied to Jacobian Assembly for an Implicit Compressible CFD Solver

Mohamed Tadjouddine, Shaun A Forth  & Ning Qin

Published in 
International Journal for Numerical Methods in Fluids , Volume 47 , Issue 10-11 (January 2005) pp 1315 - 1321.
Special Issue: 8th ICFD Conference on Numerical Methods for Fluid Dynamics . Issue Edited by Mike J. Baines, Mike J.P. Cullen, Chris Farmer, Mike B. Giles, M. Rabbitt. 

Presented at
The ICFD Conference for Numerical Methods in Fluid Dynamics, Oxford, 29th March-1st April 2004

Abstract 
In CFD, Newton solvers have the attractive property of quadratic convergence but they require derivative information. An efficient way of computing derivatives is by algorithmic differentiation (AD) also known as automatic differentiation or computational differentiation. AD allows us to evaluate derivatives, usually at a cheap cost, without the truncation errors associated with finite-differencing. Recently, efficient and reliable AD tools for evaluating derivatives have been published. In this paper, we use some of the best AD tools currently available to build up the system Jacobian involved in the solution of a finite-volume parabolized Navier-Stokes (PNS) solver. Our aim is to direct scientists and engineers confronted with the calculation of derivatives to the use of AD and to highlight those AD tools that they should try. Moreover, we introduce an AD tool that produces Jacobian code that runs usually twice as fast as that from conventional AD tools. We further show that the use of AD increases the performance of a Newton-like solver for the PNS equations.

Download
Authors' uncorrected PDF:
mt_ijnmf_05.pdf (0.4 MB) 
Journal Web Entry:  http://www3.interscience.wiley.com/cgi-bin/abstract/109880310/ABSTRACT

AMOR home