TY - JOUR
T1 - A thermal multi-phase flow model for directed energy deposition processes via a moving signed distance function
AU - Zhao, Ze
AU - Zhu, Qiming
AU - Yan, Jinhui
N1 - Funding Information:
The research is partially supported by the ASME Robert M. and Mary Haythornthwaite Research Initiation Award, United States of America and Singapore National Research Foundation, Singapore (NRF2018-ITS004-0011). The simulations were performed at the Texas Advanced Computing Center (Tacc) through a startup allocation (CTS20014). These supports are greatly acknowledged.
Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2021/1/1
Y1 - 2021/1/1
N2 - Thermal multi-phase flow analysis has been proven to be an indispensable tool in metal additive manufacturing (AM) modeling, yet accurate and efficient simulations of metal AM processes remains challenging. This paper presents a flexible and effective thermal multi-phase flow model for directed energy deposition (DED) processes. Departing from the data-fitted or presumed deposit shapes in the literature, we first derive a deposit geometry model based on an energy minimization problem with a mass conservation constraint. Then, an interface-capturing approach based on a signed distance function that moves with the laser is constructed to represent the air–metal interface evolution. The approach can be applied to any type of mesh without requiring the activation process of solid elements in a mesh. The coupled multi-phase Navier–Stokes and energy conservation equations are solved by a variational multi-scale formulation (VMS). A density-scaled continuous surface force (CSF) model is employed to incorporate the Marangoni effect, no penetration boundary condition, and the heat source on the air–metal interface. We utilize the proposed method to simulate two representative metal manufacturing problems. The simulated results are carefully compared with available experimental measurements and computational results from others. The results demonstrate the accuracy and modeling capabilities of the proposed method for metal AM problems.
AB - Thermal multi-phase flow analysis has been proven to be an indispensable tool in metal additive manufacturing (AM) modeling, yet accurate and efficient simulations of metal AM processes remains challenging. This paper presents a flexible and effective thermal multi-phase flow model for directed energy deposition (DED) processes. Departing from the data-fitted or presumed deposit shapes in the literature, we first derive a deposit geometry model based on an energy minimization problem with a mass conservation constraint. Then, an interface-capturing approach based on a signed distance function that moves with the laser is constructed to represent the air–metal interface evolution. The approach can be applied to any type of mesh without requiring the activation process of solid elements in a mesh. The coupled multi-phase Navier–Stokes and energy conservation equations are solved by a variational multi-scale formulation (VMS). A density-scaled continuous surface force (CSF) model is employed to incorporate the Marangoni effect, no penetration boundary condition, and the heat source on the air–metal interface. We utilize the proposed method to simulate two representative metal manufacturing problems. The simulated results are carefully compared with available experimental measurements and computational results from others. The results demonstrate the accuracy and modeling capabilities of the proposed method for metal AM problems.
KW - Additive manufacturing
KW - Directed energy deposition
KW - Thermal multi-phase flow
KW - Variational multi-scale formulation
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U2 - 10.1016/j.cma.2020.113518
DO - 10.1016/j.cma.2020.113518
M3 - Article
AN - SCOPUS:85096238309
SN - 0374-2830
VL - 373
JO - Computer Methods in Applied Mechanics and Engineering
JF - Computer Methods in Applied Mechanics and Engineering
M1 - 113518
ER -