Modelacao e calculo de sistemas de combustao com pre mistura no interior de meios porosos.

A two dimensional model for the study of fluid flow, heat transfer and combustion in porous burners was developed. This model is based on a semi heuristic volume averaged form of the mass momentum, energy and major species conservation equations, closed with assitional models, which describe the combustion, radiation and pressure drop in porous inert media. Two porous burners with embodied heat exchangers were simulated and the predicted temperature fields and N O and CO emissions were compared to experimental data published in the literature. The two porous burners studied were developed for household heating and have a higher degree of complexity than the simple laboratory models simulated in the majority of the papers published so far. In this thesis, the sensitivity of the results to the operating of the papers published so far. In this thesis, the sensitivity of the results to the operating conditions and to a change in the most influent parameters (radiative properties, convective heat transfer coefficient and thermal conductivity) was analysed. In addition, a more detailed study of the radiation and combustion models in porous media was performed and a porous heat exchanger was studied, being the influence of the contact resistance and of the effective thermal conductivity quantified.Available from Fundacao para a Ciencia e a Tecnologia, Servico de Informacao e Documentacao, Av. D. Carlos I, 126, 1249-074 Lisboa, Portugal / FCT - Fundação para o Ciência e a TecnologiaSIGLEPTPortuga