Numerical Investigation of Confined Flow Around Circular and Square Obstacles Using the Multiple Relaxation Time Lattice Boltzmann

Flow behavior can be affected by several parameters such as fluid properties, geometries shapes and work conditions. This paper attempts to present 2D numerical analysis of an incompressible fluid flow around circular and square cylinders using the lattice Boltzmann method with multiple relaxation time model (LBM-MRT). All simulations are carried out for fixed Reynolds number Re=100. Parabolic velocity profile was imposed in the channel entrance, while no-slip boundary conditions are adopted for walls and zero momentum flux in the outlet. Effects of obstacle shape, position, and dimensions on the lift and drag coefficients are studied and discussed. The combined consideration of these obstacle parameters for the two different geometries provides insight into their coupled influence on confinement effects and wake development. It was found that values of the drag coefficient around cylinder increase by increasing the cylinder hydraulic diameter and as position approaches the outlet.