A New Pressure Boundary Condition of Lattice Boltzmann Method (LBM) for Fully Developed Pressure-Driven Periodic Incompressible Fluid Flow

In this paper, a new pressure boundary treatment of lattice Boltzmann method (LBM) for fully developed pressure-driven periodic incompressible fluid flow is proposed. The pressure gradient, instead of equivalent body force, has been applied to determine the particle distribution function on the periodic traverse sections for the fully developed pressure-driven periodic flow. Numerical simulations, including 2D pressure-driven Poiseuille flow and fluid flow passing square obstacles, are carried out using this new boundary treatment. Simulation results show that the proposed approach not only overcomes the nonphysical inlet and outlet flow disturbances (which the LBM simulation always suffers from using the existing pressure boundary methods), but also preserves the system periodicity and generates consistent pressure distribution with macroscopic periodic boundary conditions for the pressure-driven incompressible fluid flow.