Modelling of combustion and heat transfer in 'Swiss roll' micro-scale combustors

A two-dimensional numerical model is developed to simulate combustion and heat transfer in 'Swiss roll' combustors (SRC). This model couples heat transfer and chemical reaction in the gas and heat diffusion in the conducting walls. The goal of the model is to gain insight into micro-scale combustion to prevent the occurrence of extinction. In the numerical modelling, the 'Swiss roll' geometry is unwrapped into a straight channel, with heat recirculation between the unburnt and burnt gas being appropriately taken into account. The simulation is carried out using a fourth-order scheme to discretize the spatial variables, with time integration to steady state, based on a first-order Runge-Kutta scheme. We investigate the extinction mechanisms and heat transfer characteristics in the combustor, and perform parametric studies to examine their effects on combustion and extinction. Numerical predictions of extinction limits agree well with experimental data.