Numerical simulation of vortex combustion for various air-fuel configurations

Abstract

The purpose of this research is to study the effect of various air-fuel inlet configurations to the asymmetric vortex combustor in the non-premixed combustion of methane-air mixture using the standard k-ε turbulent model on Fluent Ansys commercial CFD software. In this study, the investigation is mainly emphasizes the influence of varying the numbers of air inlet of the vortex combustor. The simulation study has been perform in two conditions which are on cold flow (non-reacting flow) using air to define the structure of vortex flow inside the vortex combustor and also on reacting flow with mixture reaction on various equivalence ratio and various configuration numbers of air-inlets. From the isothermal simulation with air, the non-reacting flow field study was found maintain the forced-vortex azimuthal velocity patterns with strongly decaying vortex structure as per previous study. A central recirculation zone (CRZ) and two secondary recirculation zone (SRZ) also found develop in the asymmetric combustor however the size of CRZ and SRZ to be found depend on the velocity inlet magnitude and numbers of air inlet port. The study on reacting flow conditions revealed by increasing the numbers of air inlet, a better chaotic mixing observed at the bottom of the combustor which judged from the temperature distributions contour in the vortex combustor. The local temperature inside the vortex combustor observed proportional to equivalence ratio. The trend of the flame height observed proportional to equivalence ratio and predicted between 10 mm to 50 mm which is comparable to previous investigation.