混合LES-RANS模型在结晶器钢液流场模拟中的应用  

Application of the hybrid LES-RANS model in the fluid flow simulation of molten steel in a mold

作　　者：茅晓慧[1,2] 李京社[1,2] 张江山[1,2] 唐海燕[1,2] 吉传波[3] 

机构地区：[1]北京科技大学钢铁冶金新技术国家重点实验室,北京100083 [2]北京科技大学冶金与生态工程学院,北京100083 [3]北京航空材料研究院先进高温结构材料重点实验室,北京100095

出　　处：《北京科技大学学报》2014年第5期608-616,共9页Journal of University of Science and Technology Beijing

基　　金：国家自然科学基金资助项目(51074021)

摘　　要：采用了一种新的混合LES-RANS(大涡模拟-雷诺平均模型)湍流模型模拟结晶器中钢液的流场.模型通过修正湍流黏度系数对水口和结晶器内湍流进行过滤,对大尺度的湍流直接采用Navier-Stokes方程求解计算,对小尺度的脉动采用标准k-ε模型进行计算.该模型能避免RANS的过分耗散并且能捕捉到更多的瞬态湍流信息.模型通过对连铸结晶器内液态金属GaInSn模型速度进行测量验证,速度测量方法为超声波多普勒测速仪(UDV)测速法.新模型与实验测量值吻合程度明显好于RANS模拟的结果,能更准确地预测结晶器和水口内的湍流行为.结晶器内瞬态流动特征表明,水口两侧流体呈周期性的偏流,周期约为5s.ABSTRACT A novel hybrid LES-RANS （ large eddy simulation-Reynold average Navier-Stokes） turbulent model was introduced to simulate fluid flow in a mold. The model employs the method of grid filtering which calculates the Navier-Stokes equation directly for large-scale eddies and calculates the standard k-ε equations for small-scale fluctuations by modifying the turbulent viscosity coefficient to simulate the flow field of molten steel. The modified eddy viscosity in the LES-RANS model can avoid the excessive diffusive nature of the RANS model and capture the transient features of turbulent flow. In this work, turbulent flow in a liquid metal （ GaInSn） model of continuous casting was measured by ultrasonic Doppler velocimetry （ UDV） . It is shown that compared with the RANS model, the results of the LES-RANS model are more identical with measured data, so the LES-RANS model can more accurately predict the turbu-lence structure. The characteristics of transient flow in the mold show that bias flow at the two sides of the nozzle changes periodically and the period is about 5 s.

关 键 词：连铸 结晶器 湍流 流场 模拟 

分 类 号：TF777.1[冶金工程—钢铁冶金]