A Direct Forcing Immersed Boundary Method Based Lattice Boltzmann Method to Simulate Flows with Complex Geometry

In the present study, a lattice Boltzmann method based new immersed boundary technique is proposed for simulating two-dimensional viscous incompressible flows interacting with stationary and moving solid boundaries. The lattice Boltzmann method with known force field is used to simulate the flow where the complex geometry is immersed inside the computational domain. This is achieved via direct-momentum forcing on a Cartesian grid by combining "solid-body forcing" at solid nodes and interpolation on neighboring fluid nodes. The proposed method is examined by simulating decaying vortex, 2D flow over an asymmetrically placed cylinder, and in-line oscillating cylinder in a fluid at rest. Numerical simulations indicate that this method is second order accurate, and all the numerical results are compatible with the benchmark solutions.