The Experimental Study And Mechanism Analysis Of Ch₄/o₂/n₂ Combustion Using Femtosecend Laster Induced Plasma

In recent years, with the advancement in aerospace technology, the developmentof large-thrust rocket and ramjet combustion needs fuel combustion reation rate of ahigher requirements. If the aircraft engine combustion chamber to generate plasma, itwill produce a large number of particles with the chemical activity, its adjacent regionof the combustion condition. Diffusion of high-energy particle wave disturbance canenhance the gas turbulence, and promote fuel atomization, vaporization and mixingwith the air, increasing the flame front and the fresh mixture and the contact area, inorder to achieve enhanced combustion stability, improved the combustion of efficiencyand reduce exhaust pollution. A new method of the excitation of vibrational orelectronic states of reacting molecules is brought up in order to reduce the activeenergy and increase the rate of chemical reaction.In this paper, we are combination of plasma combustion technology and laserexcitation of the relevant theory, analyzed the available experimental conditions,experimental ideas, build a laser combustion platform. Methane as fuel, we studyflame propagation characteristics of CH₄/O₂/N₂ combustion with plasma-assistedcombustion by using CCD, spectrum analyzer, image processing technology and thebunsen burner.In our experimental study of plasma-assisted combustion, we foundlaser produce two oxygen atoms that is 777.4nm and 844.6nm wavelengths oxygenatoms by plasma-assisted combustion, it can increase the chemical reaction rate ofmethane combustion and flame propagation speed, thereby enhancing the gascombustion stability; the same time, we simulation to the initial reactants CH₄/O₂/N₂add 777.4nm, 844.6nm wavelength of the excited state of oxygen atoms occurs withCHEMKIN, found that increasing the concentration of oxygen atoms can significantlyimprove the flame propagation speed. This is a very good explanation of the mainmechanism of femtosecond laser combustion, oxygen atoms can promote the chemicalreaction, thereby enhancing the chemical reaction rate. With experimental study, alsoverified by plasma-assisted combustion inspired oxygen atoms, enhance the flamepropagation speed of CH₄/O₂/N₂ combustion, so as to achieve the effect of plasmaassistedcombustion.