Phase-field lattice-Boltzmann investigation of dendritic evolution under different flow modes

ABSTRACT

Numerical modelling offers an effective method to investigate the effect of convection on dendritic growth; however, the current numerical approach to modelling convection behaviour is simplified, e.g. only simulating a shear flow by setting a constant inlet velocity and a zero-velocity-gradient outlet boundary condition. In this work, based on a phase-field lattice-Boltzmann approach, the effect of various flow modes on dendritic growth is investigated by introducing an external force term to induce flow. Numerical tests (2-D and 3-D) validate that the results according to the force-induced flow agree well with those by the velocity-imposed flow. Intricate convection effects under complex boundary conditions are discussed in detail. Furthermore, this force-induced flow mode allows additional freedom by eliminating the restriction on the initial position of the nuclei, which provides new ways to the microstructure modelling under complex convection.

KEYWORDS:

• Dendritic growth
• forced convection
• phase-field simulation
• solidification

Acknowledgments

The authors would also like to thank the National Laboratory for Information Science and Technology in Tsinghua University for access to supercomputing facilities.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work is financially supported by the Joint Funds of the National Natural Science Foundation of China [grant number U1537202], the Tsinghua-General Motors International Collaboration Project [grant number 20153000354], the Tsinghua University Initiative Scientific Research Program [grant number 20151080370], and the Tsinghua Qingfeng Scholarship [grant number THQF2018-15].