Flame stability enhancement and output performance optimization of a dual reaction zone recirculating micro-combustor

•A regenerative dual-reaction zone combustor enhances flow-heat synergy.•Structural parameters are varied to ensure flame stability and output performance.•Baffle length greatly affects temperature uniformity and wall radiation output.•The inlet-to-outlet ratio of 1:15 achieves a 4.6 W rise in output power.•Optimal flame length of 38.6 mm with a temperature deviation of 30 K is obtained. In micro-scale combustion, large heat loss and short residence time can easily lead to flame instability and even extinction. To enhance heat and mass transfer inside the combustor, a regenerative dual-reaction zone combustor was designed by integrating excess enthalpy combustion and flow field optimization. Through the construction of a three-dimensional numerical calculation model, the internal flow-heat synergistic enhanced combustion mechanism of the new combustor was clarified. The variations in flame shape and stationary position, the temperature distribution characteristics of the primary and secondary combustion zones, and the output characteristics of the outer wall for different inlet and outlet areas and baffle lengths are discussed in detail. It is found that enlarging the main combustion zone reduces the flame position and extends the range of stable temperatures. Even at low flow rates, the output power of the outer wall in the combustor with a 1:15 inlet and outlet cross-section ratio is 4.6 W higher compared to the combustor with a 1:5 ratio. Furthermore, increasing the baffle length effectively enhances wall temperature uniformity and wall radiation output. For a baffle length of 50 mm, the standard deviation of wall temperature is only 30 K, and the radiant energy reaches 80 W. The present work can provide references for enhancing flame stability and the design of high-output performance combustors under micro-scale conditions.