Experimental Study on Microwave-Assisted Ignition and Combustion Characteristics of ADN-Based Liquid Propellant

Microwave-assisted ignition is a new ignition method, which has the advantages of reliable ignition and high ignition energy and requires no preheating. In this study, experimental methods were used to study the microwave-assisted ignition and combustion characteristics of ADN-based liquid propellant, and the effects of microwave power and propellant flow rate on combustion flame structure, spectral emission characteristics, and flame temperature were investigated. In the experiment, a microwave-assisted ignition experimental device was established first. The ADN-based liquid propellant was injected into the microwave high-energy region from the bottom of the resonator through a hollow straight tube with an inner diameter of 1 mm, and the gas was introduced in a coaxial manner. The research results demonstrated that when the microwave power increased from 1000 to 2000 W, the flame height increased from 11.12 to 17.32 mm; the free radical intensity of C₂*, NH₂, and HNO* increased significantly; the flame temperature increased by about 28.9%. The increase in microwave power is helpful to the generation of intermediate products and the combustion performance of propellant is better. When the propellant flow rate was increased from 25 to 45 mL/min, it was found that the spray combustion effect was the best when the propellant flow rate was 30 mL/min, the flame height increased by 25.2%, and the flame temperature increased by about 11.3%.