Abstract: Coherent jet is widely adopted in electric arc furnace (EAF) steelmaking to promote molten-bath fluid flow, accelerate the metallurgical reaction, and improve the quality of molten steel.A water model experiment was conducted and a computational fluid dynamics (CFD) model was established to validate the theoretical model of penetration depth, which was built and modified by mathematical analysis.Resultsshow that the impact law of the coherent jet is similar to that of conventional supersonic jet.With the same jet condition, the penetration depth decreases as the lance height increases.At the same lance height, the penetration depth of the coherent jet is greater than that of the conventional supersonic jet as indicated by the higher k value and jet gas density of the former.