Constructal design combined with entropy generation minimization for solid-gas reactors

This paper deals with solid-gas reactors optimization. The constructal approach and the entropy generation minimization method are used for this investigation. Two kinds of reactors are considered: a basic reactor and constructal reactors with different scales, from 1 to i scales. It is demonstrated that, for a given volume and a power density of a reactor, the more the constructal scale increases the less the reactor generates entropy. However, from our model, it is useful to stop the construction at the constructal I reactor level. Furthermore, to approach the problem to a realistic case, taking into account the two dimensionality of the heat and mass fluxes, a numerical model was performed. Then, a comparison is made between numerical and analytical results. Numerical results qualitatively agree with the analytical ones but many differences exist between them when considering their quantitative aspect. These differences were discussed basing on the reactive material density. (C) 2005 Elsevier SAS. All rights reserved.