Comparative analysis of combustion stability and flow performance in micro combustor based on the synergistic action of slotted blunt body and front-baffle

Abstract

Flame instability is a key problem that needs to be solved, and the existing improvement methods are still insufficient. Different from the traditional single structure improvement, a novel synergistic combustion stabilization method is proposed. In this paper, the conventional blunt body is slotted to achieve “graded combustion”, and the front baffle is embedded on the slotted blunt body to guide fuel flow, thus strengthening the combustion and improving the flame stability. With the help of simulation software Fluent, the combustion characteristics of conventional blunt body micro combustor (CMC), conventional slotted blunt body micro combustor (MCESB) and front-baffle slotted blunt body micro combustor (MCESB-FA) are compared, and further researched the flow characteristics and inlet velocity. According to the findings, the synergistic action of slotted blunt body and baffle is beneficial to improve combustion performance and flame stability, MCESB-FA demonstrates the highest combustion efficiency, the flame breaking limits of the MCESB-FA up to 80 m/s. Besides, the turbulent kinetic energy behind the blunt body is significantly increased, which is conducive to the heat transfer for the central combustion zone and the cold fuel on both sides, so as to achieve strengthening combustion. Interestingly, the backflow area disappears due to the slotting, but the front-baffle embedding breaks the original fuel flow balance and re-forms the backflow area to achieve steady combustion. Finally, as inlet velocity increase, the MCESB-FA and MCESB have better combustion performance and flow distribution, especially under the combination of slotted blunt body and front-baffle.