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采用大涡模拟研究连铸钢水非定常湍流特性,比较了雷诺平均数学模型与大涡模拟数学模型对预测结晶器内钢水湍流运动的影响.模型采用一种低温液态金属模型的超声波多普勒速度仪(UDV)的测量结果进行验证,表明大涡模拟比雷诺平均模拟与实验测量结果更加吻合.瞬态湍流研究表明,大涡模拟优于雷诺平均数学模型,能够捕捉到水口附近高频率的湍流脉动现象.水口出流钢水区域内小尺度湍流结构起支配作用,射流以阶梯状上下摆动向结晶器内扩散.受湍流大尺度作用,结晶器内流场偏流现象始终存在,并且呈周期性变化,随着对流场时间平均的增加,结晶器内的不对称现象逐渐消除.
The large-eddy simulation is used to study the unsteady turbulent flow characteristics of continuous casting molten steel, and the effects of Reynolds averaged mathematical model and large eddy simulation mathematical model on predicting the turbulent flow of molten steel in the mold are compared.The model uses a low temperature liquid metal model of ultrasonic Doppler Velocity (UDV) measurement results show that the large eddy simulation is more consistent than the Reynolds averaged simulation and experimental measurements.Transient turbulence studies show that large eddy simulation better than the Renault average mathematical model, can capture the high frequency near the nozzle Turbulent pulsation phenomenon. The small-scale turbulent structure in the outflowing molten steel in the outlet plays a dominant role, and the jet flows up and down in the mold up and down to the mold. Due to the large-scale turbulence effect, the drift in the flow field in the mold always exists, As the time-averaged convection field increases, the asymmetry in the mold is gradually eliminated.