2017/10/12 by Farzaneh Hajabdollahi, Hajabdollahi, Farzaneh, Kannan N. Premnath +1
Engineering · #Aerosol Filtration and Electrostatic Precipitation #Cellular Automata and Lattice Gases (nlin.CG) #Computational Physics (physics.comp-ph) #FOS: Physical sciences #Fluid Dynamics (physics.flu-dyn) #Fluid Dynamics and Turbulent Flows #Lattice Boltzmann Simulation Studies
paper · pdf · doi:10.48550/arxiv.1710.04751
openalex publication_date 2017/10/12 · openalex created_date 2022/10/01 · openalex updated_date 2026/07/28
Fluid motion driven by thermal effects, such as that due to buoyancy in\ndifferentially heated three-dimensional (3D) enclosures, arise in several\nnatural settings and engineering applications. It is represented by the\nsolutions of the Navier-Stokes equations (NSE) in conjunction with the thermal\nenergy transport equation represented as a convection-diffusion equation (CDE)\nfor the temperature field. In this study, we develop new 3D lattice Boltzmann\n(LB) methods based on central moments and using multiple relaxation times for\nthe three-dimensional, fifteen velocity (D3Q15) lattice, as well as it subset,\ni.e. the three-dimensional, seven velocity (D3Q7) lattice to solve the 3D CDE\nfor the temperature field in a double distribution function framework. Their\ncollision operators lead to a cascaded structure involving higher order terms\nresulting in improved stability. In this approach, the fluid motion is solved\nby another 3D cascaded LB model from prior work. Owing to the differences in\nthe number of collision invariants to represent the dynamics of flow and the\ntransport of the temperature field, the structure of the collision operator for\nthe 3D cascaded LB formulation for the CDE is found to be markedly different\nfrom that for the NSE. The new 3D cascaded (LB) models for thermal convective\nflows are validated for natural convection of air driven thermally on two\nvertically opposite faces in a cubic cavity enclosure at different Rayleigh\nnumbers against prior numerical benchmark solutions. Results show good\nquantitative agreement of the profiles of the flow and thermal fields, and the\nmagnitudes of the peak convection velocities as well as the heat transfer rates\ngiven in terms of the Nusselt number.\n