Laser Ignition and Combustion Characteristics in NH₃/C₃ H₈ Flow

This study, based on a flow ignition platform, investigates the flame development process, minimum ignition energy(MIE), CH emission and distribution, flame development area, and flame front velocity of NH₃/C₃H₈ premixed gas using laser ignition under various equivalence ratios and propane blending ratios. The results indicate that the effect of equivalence ratio on MIE is nonlinear, with its minimum value shifting towards the richer side as the blending ratio increases. The influence of increasing blending ratio on MIE gradually diminishes. CH* is primarily distributed in regions with strong reactions, such as the flame boundary and the junction of the “three-lobed” flame. The equivalence ratio has a greater impact on the peak time of CH^* than the blending ratio. When the mixture is rich, backfire is likely to occur, whereas when the mixture is too lean, the flame experiences severe oscillations. As the equivalence ratio and blending ratio increase, the flame front velocity increases significantly, while the flame surface at the rear becomes more irregular due to the effects of incoming gas resistance and flame outflow from the front.