76th Annual Meeting of the Division of Fluid Dynamics
Sunday–Tuesday, November 19–21, 2023;
Washington, DC
Session L13: CFD: General I
8:00 AM–10:36 AM,
Monday, November 20, 2023
Room: 143C
Chair: Peter Brady, Los Alamos National Laboratory
Abstract: L13.00004 : Finite volume lattice Boltzmann scheme on unstructured meshes for simulating incompressible flows
8:39 AM–8:52 AM
Abstract
Presenter:
Akshay S Dongre
(Michigan Technological University)
Authors:
Akshay S Dongre
(Michigan Technological University)
Song-Lin Yang
(Michigan Technological University)
In the last three decades, lattice Boltzmann method (LBM) has gained popularity as an alternative to Navier-Stokes equation (NSE) for simulating fluid flow and heat transfer. Simplicity of numerical algorithm and computational efficiency are the most significant advantages of LBM. Although coupling of velocity discretization to the spatial discretization facilitates exact treatment of the advective terms in LBM, it not only restricts the implementation of LBM on non-uniform grids, thus, limiting mesh adaptation for complex flows on irregular geometries but also imposes strict stability requirements on the LBM formulation. Also, LBM, in its standard form, suffers from compressibility error affecting its accuracy for simulating incompressible flows. Adapting the lattice Boltzmann equation (LBE) for the finite volume approach can alleviate some of the restrictions. Therefore, the goal of the present study is to adapt LBM for the finite volume approach implemented on unstructured meshes using a true incompressible LBM (iLBM) model to overcome the challenges mentioned above. In the finite volume LBM (FVLBM) approach, the particle advection can be solved using the techniques developed to solve advective terms in the NSEs. In the current study, advective terms have been solved using the Monotonic Upstream-centered Scheme for Conservation Laws (MUSCL) scheme. A fully incompressible model, recovering the incompressible unsteady NSEs, developed previously for the standard LBM approach has been incorporated in the FVLBM formulation. Several canonical flow problems have been simulated using the FVLBM-MUSCL formulation. Qualitative as well as quantitative results are presented. The iLBM model shows substantial improvements over the standard LBM model while simulating flow in a lid driven cavity, flow over a backward facing step, and transient pulsating flow showcasing the accuracy and the applicability of the iLBM model in the FVLBM-MUSCL framework for simulating fluid flows for a broad range of conditions.