A comparative study of interface-conforming ALE-FE scheme and diffuse interface AMR-LB scheme for interfacial dynamics

In this work, a comparative study for two simulation methods is conducted for interfacial flows in two dimensions: an arbitrary Lagrangian Eulerian (ALE) finite element method (FEM) on interface-conforming meshes and a phase field lattice Boltzmann method (LBM) on Cartesian meshes with quadtree adaptive mesh refinement (AMR). The methods are validated by simulations of a bubble without and with buoyancy force. In particular, a suspended bubble with initial nonequilibrium shape and a rising bubble driven by buoyancy force are simulated to validate the methods. Additional simulations of the breakup of a rising bubble and the bubble interaction with a horizontal wall are used to quantify the efficacy and efficiency of the two methods. It is observed that the phase field LBM is more dissipative due to the nature of the diffuse interface method used to capture the interfaces. Overall, the results obtained from both methods agree well with each other when the effects due to the numerical artifacts intrinsic to the diffuse interface method can be neglected. Also, the LBM is in general more efficient and easier to be parallelized

Numerical modelling of additive manufacturing process for stainless steel tension testing samples

Nowadays additive manufacturing (AM) technologies including 3D printing grow rapidly and they are expected to replace conventional subtractive manufacturing technologies to some extents. During a selective laser melting (SLM) process as one of popular AM technologies for metals, large amount of heats is required to melt metal powders, and this leads to distortions and/or shrinkages of additively manufactured parts. It is useful to predict the 3D printed parts to control unwanted distortions and shrinkages before their 3D printing. This study develops a two-phase numerical modelling and simulation process of AM process for 17-4PH stainless steel and it considers the importance of post-processing and the need for calibration to achieve a high-quality printing at the end. By using this proposed AM modelling and simulation process, optimal process parameters, material properties, and topology can be obtained to ensure a part 3D printed successfully