A multi-mesh MPM for simulating the meshing process of spur gears

A numerical scheme is presented to simulate the meshing process of spur gears, based on the material point method (MPM). To allow engagements at successive contact points and subsequent separation between neighboring gear teeth, a contact/sliding/separation procedure in a multi-mesh environment without using master/slave nodes is proposed so that the no-slip contact constraint inherent in the existing MPM can be released. Individual drive members rotate around corresponding axes, through which simulated angular velocity transmission is in good agreement with the analytical solution. It appears from the simulation results presented here that the multi-mesh MPM could become a robust spatial discretization tool for gear design problems that involve large rotation, contact/sliding and separation.     

Implementing a high accuracy Multi-Mesh Method for incremental Bulk Metal Forming

The demand for the simulation of incremental bulk forming processes is high. However, the computation times for such simulations are still unsatisfactorily long and thus, their application is deterred. To accelerate the simulations, a multi-mesh algorithm was implemented in the Finite-Element simulation package PEP&LARSTRAN/Shape. This method uses a FE mesh which is fine in the deformation zone and coarse in the remaining areas. A second mesh, fine over the entire volume, is used to store computed values and to minimize the loss of accuracy. The method was tested on an open die forging process and adapted for ring rolling. This paper describes the latest further developments of the method in [1], for instance tool kinematics, remeshing and data transfer and compares its results to conventional models, thereby showing its performance and accuracy.     

A modified two-stage pulse tube cryocooler utilizing double-inlet and multi-mesh regenerator

In this paper a thermally coupled Stirling-type two-stage pulse tube cryocoolers (TSPTC) is studied using a one-dimensional (1-D) CFD code. After validating the results of the simulations, effects of synchronous utilization of multi-mesh regenerator and double-inlet on the performance of the TSPTC are investigated. Results of simulations show that non-oscillating friction factors do not possess sufficient accuracy for calculation of oscillating friction losses in non-porous media. Whereas, using oscillating friction factor of non-porous media leads to sufficient accurate results. According to the results, using multi-mesh regenerator and double-inlet increases the COP and decreases the minimum attainable temperature of the system. It is observed that a minimum temperature of 18.2 K is attainable using optimum multi-mesh regenerator and double-inlet; whereas, for a simple TSPTC with a uniform mesh regenerator, a minimum temperature of 26.4 K is concluded.     

Computation of Dendritic Growth with Level Set Model Using a Multi-Mesh Adaptive Finite Element Method

In this paper, we propose an efficient multi-mesh h-adaptive algorithm to solve the level set model of dendritic growth. Since the level set function is used to provide implicitly the location of the phase interface, it is resolved by an h-adaptive mesh with refinement only around the phase interface, while the thermal field is approximated on another h-adaptive mesh. The proposed method not only can enjoy the merits of the level set function to handle complex evolution of the free boundary, but also can achieve the similar accuracy as the front tracking method for the sharp interface model with about the same degrees of freedom. The algorithm is applied to the simulation of the dendritic crystallization in a pure undercooled melt. The accuracy is verified by comparing the computational dendrite tip velocity with solvability theory. Numerical simulations, both in 2D and 3D cases, are presented to demonstrate its capacity and efficiency.