Behaviour of Semisolid Slurry Flows through a Channel
Behaviour of Semisolid Slurry Flows through a Channel
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半固体浆料流过通道的行为
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
H. Chattopadhyay
中科院分区：
文献类型：
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作者：
S. Simlandi;N. Barman;H. Chattopadhyay
在半固态合金的金属板成形的情况下，该过程的建模对于预测合金的流动行为、温度分布等对于提高产品质量和降低制造成本是非常重要的。因此，本工作开发了一个模型来预测金属板成形过程中的一种铝合金（A356）在半固态状态。半固态合金通过具有小深度和较大宽度的矩形通道。半固态的合金以受控的速率从顶部冷却。在该模型中，相应的流场由动量守恒方程表示。考虑到Herschel-Bulkley模型，半固态浆料的非牛顿行为被纳入。悬浮颗粒在剪切作用下的团聚和解聚现象用一个随时间变化的结构参数来表示。考虑瞬态能量守恒方程预测温度场，从而不断更新固相分数。该解考虑了半固态合金的表观粘度作为结构参数、剪切应力和剪切速率的函数。最后用有限差分法求解控制方程。预测了半固态浆料的速度、温度和液相分数分布。
In case of metal sheet forming of alloys in semisolid state, modelling of the process is very essential to predict flow behaviour, temperature distribution of the alloy etc. towards improvement of the product quality and to reduce manufacturing costs. Accordingly, the present work develops a model to predict the behaviour during metal sheet forming of an Al-alloy (A356) in semisolid state. The semisolid alloy passes through a rectangular channel having small depth and larger width. The alloy in semisolid state is cooled from the top at a controlled rate. In the model, the respective flow field is represented by the momentum conservation equation. The non-Newtonian behaviour of the semisolid slurry is incorporated considering the Herschel–Bulkley model. The agglomeration and de-agglomeration phenomena of the suspended particles under shear are represented using a time dependent structural parameter. The temperature field is predicted considering the transient energy conservation equation, and hence the fraction of solid is continuously updated. The solution considers an apparent viscosity of the semisolid alloy as a function of structural parameter, shear stress and shear rate. The governing equations are finally solved by finite difference method. The work predicts velocity, temperature and liquid fraction distribution of the semisolid slurry.