Developing mathematical modeling of the heat and mass transfer in a planar micro‑combustor with detailed reaction mechanisms

Abstract

In this study, an analytical investigation of heat and mass transfer in a planar micro-combustor with considering the detailed reaction mechanisms for a methane/air mixture is presented. The primary objective is to propose practical solutions to manage both heat and mass transfer, which are critical problems in micro-combustors. The reactive mixture is divided into pre-flame, reaction, and post-flame zones. Then, the partial differential equations of energy and species are analytically solved in each zone with regard to the detailed reaction mechanisms and matching conditions. Moreover, to make a general investigation, appropriate non-dimensional physical parameters are proposed considering interactions between reactive mixture, solid structure, and ambient. As a result, proper correlations are proposed for the wall temperature distribution under different conditions that can be suitable for the relative numerical simulations. It is shown that a maximum decrease of 45% occurs for the gas temperature at the post-flame zone when flow Peclet number is reduced by 50%. Furthermore, by increasing the solid–fluid thermal diffusion ratio from 50 to 100 and 100 to 200, the CO conversion rate is decreased around 77% and 16%, respectively.