In order to obtain the combustion characteristics of the CH4/Air premixed flame under the action of the wall interaction,a study on the impact of the jet flame on the wall at different separation distances was carried...In order to obtain the combustion characteristics of the CH4/Air premixed flame under the action of the wall interaction,a study on the impact of the jet flame on the wall at different separation distances was carried out.The separation distance from the burner outlet to the lower surface of the wall is changed and the flame structure is obtained through experiments.The temperature,velocity and reaction rate are obtained through numerical simulation,and the law of flame characteristics change is obtained through analysis.The results show that as the separation distance increases,the premixing cone inside the flame gradually changes from a horn shape to a complete cone shape and the length of the premixing cone profile increases.Also,the peak temperature and velocity of the mixture in the axial direction gradually increase,and the temperature and velocity in the radial direction first increase and then decrease.The temperature gradient and velocity reach the maximum when the separation distance is 11 mm.The peaks of reactants(CH_(4))net reaction rate intermediate products(CO)and products(CO_(2),H_(2)O)on the axis and the axial distance corresponding to the peaks increase accordingly.The chemical reaction rate near the wall also gradually decreases with the increase of the separation distance.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.51976082)and Qing Lan project.
文摘In order to obtain the combustion characteristics of the CH4/Air premixed flame under the action of the wall interaction,a study on the impact of the jet flame on the wall at different separation distances was carried out.The separation distance from the burner outlet to the lower surface of the wall is changed and the flame structure is obtained through experiments.The temperature,velocity and reaction rate are obtained through numerical simulation,and the law of flame characteristics change is obtained through analysis.The results show that as the separation distance increases,the premixing cone inside the flame gradually changes from a horn shape to a complete cone shape and the length of the premixing cone profile increases.Also,the peak temperature and velocity of the mixture in the axial direction gradually increase,and the temperature and velocity in the radial direction first increase and then decrease.The temperature gradient and velocity reach the maximum when the separation distance is 11 mm.The peaks of reactants(CH_(4))net reaction rate intermediate products(CO)and products(CO_(2),H_(2)O)on the axis and the axial distance corresponding to the peaks increase accordingly.The chemical reaction rate near the wall also gradually decreases with the increase of the separation distance.