3003铝合金铸轧熔体流热场的数值模拟研究

Numerical Simulation Study on fluid-themal Field of 3003 Aluminium Alloy Melt in Cast-Rolling

采用FLUENT流体计算软件对3003铝合金铸轧流热场进行了数值模拟分析。结果表明:铝熔体在铸嘴型腔内的流动属于湍流向层流的过渡流,应用FLUENT中的低雷诺数K・E湍流模型的计算结果精度高,收敛性好;熔体在铸嘴型腔内流动容易产生涡流,其原因是熔体通过分流块间隙时总是紧贴间隙一侧分流块的轮廓流动,导致另一侧区域充型不足形成低压“真空”区,在压力差的驱使下,熔体回流形成涡流;熔体的速度场对温度场起着决定性的作用,流速快的区域温度也相对较高。该结构的铸嘴布流不当,导致各间隙的熔体分流不均,流过各间隙的熔体速度和流量不均匀,最终使得铸嘴出口处热流场不均匀。

The numerical simulation analysis of the fluid-themal of 3003 aluminum alloy cast-rolling was carried out by using FLUENT fluid calculation software.The results show that the flow of aluminum melt in the cavity of the casting nozzle belongs to the excessive flow of the turbulent flow to the laminar flow.Using the low Reynolds number K-E turbulence model in FLUENT,the calculation results are very accurate,and astringency is good.Flow of melt in nozzle-shaped cavity easily produces the eddy vortex.The reason is that when the melt passes through the gap,it is always close to the contour flow of the shunt block on one side of the gap,resulting in insufficient filling of the other area to form a low-pressure"vacuum"area,which is driven by the pressure difference to form eddy currents.The velocity field of the melt plays a decisive role in the temperature field,and the temperature in the region with fast flow rate is relatively high.The nozzle flow of the structure is improper,resulting in uneven melt splitting in each gap,and the melt velocity and flow rate flowing through the gaps are uneven,and finally make the heat flow field at the outlet of the cast nozzle uneven.