A particle-resolved heat-particle-fluid coupling model by DEM-IMB-LBM

Abstract

Multifield coupling is frequently encountered and also an active area of research in geotechnical engineering. In this work, a particle-resolved direct numerical simulation (PR-DNS) technique is extended to simulate particle-fluid interaction problems involving heat transfer at the grain level. In this extended technique, an immersed moving boundary (IMB) scheme is used to couple the discrete element method (DEM) and lattice Boltzmann method (LBM), while a recently proposed Dirichlet-type thermal boundary condition is also adapted to account for heat transfer between fluid phase and solid particles. The resulting DEM-IBM-LBM model is robust to simulate moving curved boundaries with constant temperature in thermal flows. To facilitate the understanding and implementation of this coupled model for non-isothermal problems, a complete list is given for the conversion of relevant physical variables to lattice units. Then, benchmark tests, including a single-particle sedimentation and a two-particle drafting-kissing-tumbling (DKT) simulation with heat transfer, are carried out to validate the accuracy of our coupled technique. To further investigate the role of heat transfer in particle-laden flows, two multiple-particle problems with heat transfer are performed. Numerical examples demonstrate that the proposed coupling model is a promising high-resolution approach for simulating the heat-particle-fluid coupling at the grain level.

Keywords

• Particle-fluid interaction
• Heat transfer
• Discrete element method (DEM)
• Lattice Boltzmann method (LBM)
• Dirichlet-type thermal boundary
• Direct numerical simulation