The effect of micro-combustor material on premixed Hydrogen/air flame dynamics

Abstract

The focus of this work is the numerical study the effect of micro-combustor material on the flame dynamics in a wavy micro-channel, using premixed of Hydrogen/Air mixture, with an equivalence ratio of $\varphi$=1.0. This work extends other works in the literature which consider a linear or hyperbolic temperature profiles along the wall (or adiabatic conditions at the wall) by using a pseudo-stationary conjugated heat transfer approach to account for the effect of the type of material of the micro-combustion chamber on the flame dynamics. We examine five different groups of materials, ceramics (low and high-temperature co-fired ceramics), metals (low carbon stainless steel), amorphous materials (fused silica glass) and high thermal conductivity material (silicon alloy). For most materials, the results indicate that at lower flow rates, the flame remained stable, whereas at higher inlet velocities, it exhibited pulsating burst dynamics. Furthermore, materials possessing a high thermal conductivity exhibited less stable flames characterized by lower temperatures and reduced heat release rates. This correspondingly led to lower temperatures in the solid phase. Additionally, materials with higher thermal conductivity displayed increased heat flux values within the solid, aligning with the expected behavior.