Two-dimensional analytical investigation of conjugate heat transfer in a finite-length planar micro-combustor for a hydrogen-air mixture

Abstract

This study aims to investigate the conjugate heat transfer in a finite-length planar micro-combustor by using a two-dimensional analytical model. The primary objective is to thermally analyze the effects of ambient, solid wall, and gas mixture properties on wall and gas temperature profiles and heat recirculation via the micro-combustor wall. The micro-combustor is divided into three sections composed of pre-flame, reaction, and post-flame zones. The energy equation is solved in each zone for both wall and gas mixture regarding the matching boundary conditions. As a result, an appropriate correlation that is a combination of hyperbolic tangent and linear functions for estimating the wall temperature profile is developed. Moreover, since the absolute amounts of positive wall temperature gradient are larger than the negative ones, heat is conducted intensely toward the inlet side of wall which results in heat recirculation at pre-flame zone. These findings can be used to propose a simple approach for preliminary micro-combustor design.