A COMPARISON OF SOME OF THE THERMAL CHARACTERISTICS OF FINITE-ELEMENT AND FINITE-DIFFERENCE CALCULATIONS OF TRANSIENT PROBLEMS

Abstract
Use of the finite-element method (FEM) for the computation of transient thermal problems can lead to the anomalous result that, even in the absence of local sources of heat, temperatures near suddenly cooled boundaries show an initial increase. A spectral analysis of the FEM and finite-difference method (FDM) reveals that this anomaly is caused by overestimation of the eigenvalues. The FDM, since it represents a lower bound to these eigenvalues, does not exhibit this behavior. The spectral characteristics of the two methods are analyzed in this paper and a partial cure is offered, although the only rigorously effective method of computing short-time solutions is through the use of the FDM.

This publication has 2 references indexed in Scilit: