Effect of shrouding nozzle arrangement on the flow field characteristics of coherent jet

The coherent lance technology is widely used in the electric arc furnace (EAF) steelmaking process.It achieves a better metallurgical effect compared with the conventional supersonic lance technology.Herein, to further improve the stirring ability of the coherent lance, the effects of shrouding nozzle arrangement on the flow field and stirring ability of coherent jet were analyzed under two environment temperatures.Based on the results of the numerical simulation and combustion experiment, the characteristics of axial velocity and total temperature distributions has been introduced for researching the impaction ability of coherent jet using various shrouding nozzle arrangements.The appropriate simulation model was built by testing three types of mesh levels.The eddy dissipation concept (EDC) model and chemical kinetic mechanism were adopted to represent the combustion reactions of the O₂-CH₄jet flame in the numerical simulation process.Resultsreveals that the numerical simulation data shows good agreement with combustion experiment.The initial velocity at the exit of main oxygen Laval nozzle does not change with different shrouding nozzle arrangements.With increase in the distance between the main oxygen and shrouding nozzles, the length of the velocity potential core first increases and then reduces.Moreover, all shrouding nozzle arrangements increase the length of velocity potential core.