Energy conversion efficiency of a thermo photo voltaic (TPV) system strongly depends on the wall temperature and its uniformity. Therefore, improving heat transfer characteristics of these systems is a focus of many recent studies. Significant efforts have been devoted to investigate flame stabilization and heat transfer enhancement for straight channels; planar and circular. However, the investigation of the impact of curvature on heat transfer and flow characteristics of a reacting flow is limited, implying that more studies are required. This study explores the effect of curvature on heat transfer, pressure drop and emission levels for a circular micro-combustor with sudden expansion (backward facing step). The study uses steady state Reynolds Average Numerical Simulation (RANS) turbulence model along with a finite rate chemistry model to numerically investigate the flame structure inside a micro-combustor. The investigation observes significant enhancement in outer wall temperature and heat flux for curved ducts as compared to those for straight channels. © 2015 The Authors. Published by Elsevier Ltd.