Promoting energy efficient conversion: Synergic-improving combustion efficiency and flame stability via front baffle and slotted blunt body in a micro combustor

Low combustion efficiency and flame instability are the key problems in micro combustors, which cannot be effectively improved by a single structural design. In this paper, inspired by graded combustion in conventional combustors, we applied slotted blunt body to achieve graded combustion and used baffles to adjust slot fuel. Based on this, the effects of baffle structure parameters on combustion and flow performance were analyzed, and the adaptability of baffle angle at different inlet velocities was fully discussed. According to the findings, there exists a correlation between combustion efficiency and baffle length. Specifically, at a baffle length of 0.4 mm, the combustion efficiency reaches 93.61 %, concurrently achieving a flame breaking limit of 82 m/s. Controlling velocity at 10 m/s, the 60° baffle angle increases the combustion efficiency to 93.64 %, resulting in better temperature and flame distribution, and the 0° baffle angle achieves the best flame breaking limit. Moreover, within the velocity range of 2–40 m/s, an expansion baffle angle proves advantageous for improving combustion efficiency. Contrastingly, as the velocity increases from 50 m/s to 70 m/s, expanding the front baffle is beneficial to improve the flame breaking limit, preventing pressure loss and avoiding backflow area tearing. This research is beneficial to improve the combustion performance of micro-combustors, and has important reference value for improving the flame stability.