Metal injection moulding (MIM) is a new technology to manufacture small intricate parts in large quantity. Numerical simulation plays an important role in its development. To predict the specific segregation effect in...Metal injection moulding (MIM) is a new technology to manufacture small intricate parts in large quantity. Numerical simulation plays an important role in its development. To predict the specific segregation effect in MIM injection, mixture theory is adopted to model the injection flow by a bi-phasic model. This model conducts to the solution of two-coupled Stokes equations. It is an extremely computational consuming solution in the scope of the traditional algorithms, which induce a serious challenge to cost-effectivity of the MIM simulation. Referred to some methods proposed by Lewis in mono-phasic simulation and the implicit algorithms in MIM simulation, a new explicit algorithm is proposed and realized to perform efficiently this type of bi-phasic flow. Numerically this algorithm is devised to perform the simulation in a fully uncoupled manner except for a global solution of the pressure field in each time step. The physical coupling is taken into account in a sequential pattern by fractional steps.展开更多
Inner hydroforming is a new manufacturing technique. It presents a great importance for car manufacturing and other industries. To determine the forming process, numerical simulation will play a very important role. T...Inner hydroforming is a new manufacturing technique. It presents a great importance for car manufacturing and other industries. To determine the forming process, numerical simulation will play a very important role. To overcome the difficulties of instability and non linearity, a new algorithm is proposed. The algorithm takes the advantages of dynamic transient solution and ensures its stability by a modified Runge Kutta scheme. Adaptive step size is applied with a practically inexpensive error estimation to achieve good efficiency. Numerical examples have shown an advantage in comparison with the currently used central difference algorithm.展开更多
基金Supported by the Invited Professor Program of French Ministry of Education (No. 9808588) , the French-Chinese Advanced Research Program (M98-04)the Foundation for University Key Teacher by the Chinese Ministry of Education (GG-460-10613-2770).
文摘Metal injection moulding (MIM) is a new technology to manufacture small intricate parts in large quantity. Numerical simulation plays an important role in its development. To predict the specific segregation effect in MIM injection, mixture theory is adopted to model the injection flow by a bi-phasic model. This model conducts to the solution of two-coupled Stokes equations. It is an extremely computational consuming solution in the scope of the traditional algorithms, which induce a serious challenge to cost-effectivity of the MIM simulation. Referred to some methods proposed by Lewis in mono-phasic simulation and the implicit algorithms in MIM simulation, a new explicit algorithm is proposed and realized to perform efficiently this type of bi-phasic flow. Numerically this algorithm is devised to perform the simulation in a fully uncoupled manner except for a global solution of the pressure field in each time step. The physical coupling is taken into account in a sequential pattern by fractional steps.
文摘Inner hydroforming is a new manufacturing technique. It presents a great importance for car manufacturing and other industries. To determine the forming process, numerical simulation will play a very important role. To overcome the difficulties of instability and non linearity, a new algorithm is proposed. The algorithm takes the advantages of dynamic transient solution and ensures its stability by a modified Runge Kutta scheme. Adaptive step size is applied with a practically inexpensive error estimation to achieve good efficiency. Numerical examples have shown an advantage in comparison with the currently used central difference algorithm.
