MATHEMATICAL-MODELING OF A POROUS SILICON-BASED PELLISTOR-TYPE CATALYTIC FLAMMABLE-GAS SENSOR

The development of a three-dimensional thermal mathematical model of a pellistor based on the fundamental physical laws oi heat transfer and employing a few clearly stated simplifying assumptions concerning the convective heat transfer in ambient air is reported. The model was nu merically solved using the implicit alternating-direction finite diffe rence method. The software was written in Microsoft and Gnu C and run on a PC. Simulations for studying the transient heat transfer in the a bsence of flammable gas were performed. Refinement of the model in ter ms of reducing the simplifying assumptions and the experimental verifi cation of the simulated thermal behaviour of the model structure is in progress. In its final form the model should be capable of describing more sophisticated micro-pellistor structures. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.