Parallel Lattice Boltzmann Method for Convection in Dendritic Solidification

This work focuses on the development, validation and implementation of a parallel lattice Boltzmann method (LBM) for resolving fluid flow in multi-physics problems, such as alloy solidification, focusing on the effects on microstructure evolution. The literature has shown the importance of fluid flow in solidification as it affects the morphology and evolution of the growing dendrites. Because solute flow represents the most time-consuming part of the simulation, state-of-the-art computing allows for only a few cubic millimetres to be simulated, which is far less than the typical size of cast metal components. A purpose-built3D LBM code is fully coupled to an external cellular automata (CA)solidification solver. It is run in parallel to achieve microstructure solidification on a macroscale. The performance analysis shows that the developed LBM flow solver is several times faster than the finite difference method currently used within the research group. The CALBM approach opens the possibility of component-scale microstructural simulations in a practical time frame. To properly model the physical boundaries, a new 3D moment-based boundary method for handling velocity and pressure in LBM is proposed. The capability of the numerical model is demonstrated by replicating experimentally observable physical phenomena during freckle formation in a casting.

Name dc:type.qualificationname

phd

Level dc:type.qualificationlevel

doctoral

Grantor dc:publisher.institution

University of Greenwich

Year dc:date.issued

2018

Author dc:creator

• Krastins, Ivars

Advisors dc:contributor.advisor

• Kao, Andrew
• Pericleous, Kyriacos A
• Reis, Timothy

• Q Science (General)
• QA Mathematics
• QA75 Electronic computers. Computer science

Language dc:language

en