Abstract: Combining the standard k~ω model with the Reynolds averaged NavierStokes (RANS) equations， a compressible， nonisothermal and threedimensional CFD model was developed for the multiple nozzle supersonic jets in topblown steelmaking convertor， and the validity of the model was verified by experiment. The effect of temperature field on molecule viscosity of fluid was considered， and the dynamic properties of jets were studied in different temperature fields. The results showed that ambient temperature makes a great influence on jets velocity， temperature and density distributions. With the increase of ambient temperature， the jets density decreases，their velocity attenuation is slower， velocity is higher and radial expanding of jets is much easier. Jet is more likely to coalescence in lower ambient temperature. As jets travel in axial direction， the effect of ambient temperature on jets dynamic pressure tends to negligible. That is to say， the effect of the ambient temperature on the impacting force of jets on the bath is weakened， but impinging area increases with the increase of ambient temperature.

Key words: jets, jets coalescence, ambient temperature, BOF, CFD