Stabilization of premixed flames in narrow channels by a highly conductive embedded wall segment: Application to hydrogen-air mixtures

Abstract

This study uses numerical analysis to investigate the potential for stabilizing hydrogen-air flames within narrow channels by incorporating a wall segment of finite length with high thermal conductivity. The numerical model is based on the Navier–Stokes equations, coupled with energy and mass conservation equations for reacting gases, and incorporates detailed chemistry and transport models, including thermal diffusion (the Soret effect). For the gas–solid coupling, a novel computational method is used that avoids the expensive calculations associated with solving the unsteady conjugate gas–solid heat transfer. For the first time, we demonstrate that this innovative thermal stabilization method provides stable operation for lean hydrogen-air combustion across a wide range of reactant flow rates. This offers significant flexibility in terms of power output variation, surpassing the performance of classical counterflow heat recirculating devices. Finally, this study emphasizes the importance of incorporating the Soret effect in the species transport model to accurately compute hydrogen-containing flames, especially in highly curved flame configurations.