NUMERICAL INVESTIGATION OF UNIFORM FLOW PAST STATIONARY SPHERE USING IMMERSED BOUNDARY-LATTICE BOLTZMANN METHOD

Resumo

The Lattice-Boltzmann method (LBM) has been attracting lot of interest as a tool to solve
hydrodynamic problems, mostly due its suitability for parallelization. However, the implementation of

boundary conditions in LBM has some hardships, especially for flow domains containing immersed par-
ticles. An alternative to overcome this problem is the immersed boundary method (IBM), a numerical

technique that uses a secondary Lagrangian mesh and imposes a boundary condition through a force field.
This study presents the development of an IB-LBM based algorithm that simulates a free flow around a

stationary sphere, which can also be described as a uniform jet stream that encounters a spherical obsta-
cle. The fluid domain is described using a D3Q19 lattice arrangement and, a geodesic polyhedron based

mesh delineates the spherical boundary. The flow evolution for fluid mesh is simulated using LBGK
equation, whose stability is enhanced through regularization, a process which discards non-physical high
order moments from LBM. In order to verify algorithm consistency, this document presents comparison
with literature benchmark data of flow profiles and drag coefficients for different Reynolds numbers,
showing good agreement between present work and available studies.