【作者】 齐慧；

【导师】 杨屹；

【作者基本信息】 四川大学 ， 材料加工工程， 2002， 硕士

【摘要】 液态金属的充型过程是铸件形成的第一阶段，也是最重要的阶段，许多铸造缺陷(如卷气、夹渣、浇不足、冷隔及砂眼等)都是在充型过程中由于工艺设计不当而产生的；同时充型对于铸件的凝固过程也有着直接的影响。因此，了解并控制充型过程是获得优质铸件的重要条件。本文的主要内容是应用大型通用有限元分析软件ANSYS，并利用不可压缩粘性流体的控制方程和标准K-ε模型，对“E”形框和厚大件的流场、温度场进行了深入的研究，验证了考虑充型过程对凝固温度场的影响和最终结果精度的提高，其中采用两种不同的计算方法对模拟结果进行了比较，结果表明考虑充型过程的模拟结果相比建立在“瞬时充型”假设上的模拟结果更接近于实测温度值。 本文首次提出了在充型模拟计算中考虑流动损失因素，并把这一因素对金属液充型过程的影响作为模拟流体的流动边界条件施加到铸件充型过程的分析中，使模拟流体的边界条件更趋向于金属液的实际流动情况。通过两个实例验证了这种方法的正确性，并据此建立了基于ANSYS的考虑金属液流动损失的控制方程的数学模型。最后，对充型过程中流动损失的影响因素、流动损失与铸件结构和当量厚度的关系作了较为深入的研究。更多还原

【Abstract】 Mold filling is the first phase during a casting forming. Many casting defects, such as Slag, Cold Shuts and Poured Short, occur due to filling insufficiency condition. Therefore, it is important to understand the mold filling process in order to control it. For the reason, the flowing field and temperature field simulation were carried out by using the software ANSYS, based on the uncompressed-viscosity control equation and standard K ~ e model. The simulation results agree well to those, which were obtained by experiments. Two different methods were used to simulate fluid flow, one of which does not consider simulation of flowing process and the other does. The results showed that the second method was more accurate than the first one .In the research, it is the first time to consider the flow losing for the simulation as one of boundary conditions, and its influence on temperature field was analyzed deeply, combined with the results of experiments. And then, the mathematical model, which consists of control equations solving method and initial condition has been put forward. The results showed that consideration of flow losing during simulation would improve the accuracy of simulation. Finally, the factors of flow losing and the relationship of flow losing, casting structure and section thickness of casting were discussed thoroughly according to the results of simulations and experiments in the paper.更多还原