Development of a one-dimensional model to predict the flame temperature in cylindrical micro combustors

Abstract

Measurement of the flame temperature in a micro combustor is essentially difficult due to the size constraint. A one-dimensional (1D) flame model coupled with the heat conduction in the solid wall is employed to analyze the heat transfer occurring in a cylindrical micro combustor. The flame temperature is given explicitly by taking into account the effects of the heat loss (from the flame to the wall) in the reaction zone and heat recirculation through the solid wall. With the data obtained from the simulation results of the 1D adiabatic freely propagating CH4-air laminar flames, the flame temperature in a cylindrical micro combustor can be solved iteratively. In order to validate the 1D model, the two-dimensional (2D) numerical simulations of premixed combustion of the CH4-air mixtures are carried out in a 0.5 mm radius cylindrical micro combustor. The comparisons of the flame temperature and heat recirculation between the 1D model and 2D numerical simulation indicate that despite the simplifications and assumptions made in the present study, the 1D theoretical model is able to predict the flame temperature to a reasonable accuracy.