中文摘要：

文章基于非正交结构网格，建立了大变形铝型材非稳态挤压过程有限体积法数值模拟的数学模型。给出了非正交结构网格上有限体积法的基本控制方程，研究了非正交网格上有限体积法模拟铝型材挤压过程的关键技术。将流体体积法（VOF）应用于三维非正交网格来捕捉材料流动前沿，采用塑性剪切模型施加了摩擦边界，结合本构方程和粘度迭代，开发了铝型材挤压过程数值模拟程序。针对一大挤压比的典型薄壁铝型材挤压过程进行了数值模拟，得出了速度场、等效应力、等效应变速率等。将模拟结果与有限元软件DEFORM-3D的模拟结果进行对比，验证了该文所建立数学模型的可行性和正确性。

英文摘要：

The mathematic model for unsteady aluminum extrusion processes with large deformation using finite volume method based on non-orthogonal structure grids was established in this paper. The basic governing equations were given, and key technologies of finite volume method based on non-orthogonal structure grids for aluminum extrusion processes simulation were studied. Volume of Fluid （VOF） method was applied on 3D non-orthogonal structure grids to capture the free surface of the materials. Plastic shear friction model was used to apply friction boundary conditions. Associating with constitutive equations and dynamie viscosity iteration, the simulation program of aluminum extrusion processes was written. A typical thin-walled aluminum profile extrusion process with severe deformation was simulated, and velocities, effective stress, effective strain rate were obtained. The results were compared with those simulated by Deform-3D in the same conditions. The feasibility and accuracy of the mathematic model built in this paper were proved.