Electrical characteristics of laminar propane flame during head-on quenching

The electrical characteristics of laminar propane flame during head-on quenching were investigated experimentally and computationally.A variable small electric field was applied between the burner and the quenching plate,which recorded flame current as a function of the height of the quenching plate,for both polarities,different premixed-air volume,and quenching plate materials.More detailed information of flame,such as the distribution of OH radical and main charged species(H3O+and e-)were obtained by using numerical simulation.The results showed that during the head-on quenching,the resistance of the propane flame is on the order of 108Ω,the flame current increases with the increase of the premixed-air volume,and the effect of the quenching plate materials on the flame current is negligible.In addition,it is found that the direction of the electric field has a significant influence on the flame current,indicating the"rectifier"characteristics of the flame.Moreover,it is interestingly found that the trend of flame current for burner-(burner is negative)is more consistent with the trend of the maximum OH mole concentration than for burner+(burner is positive),which indicates that the trend of flame current for burner-can more accurately reflect the combustion state during head-on quenching.And it would be a better choice to use burner as the negative electrode when diagnosing the combustion state with an applied electric field.