On transient hybrid Lattice Boltzmann–Navier-Stokes flow simulations

Abstract

We investigate one- and two-way coupled schemes combining Lattice Boltzmann (LB) and incompressible Navier-Stokes (NS) solvers. The one-way coupled simulation maps information from a coarse-grained NS system onto LB boundaries which allows for arbitrarily complex fluid flow boundary conditions on LB side. We find that this produces accurate velocity, pressure and stress predictions in Couette, Taylor–Green and Karman vortex scenarios. The two-way coupled simulation decomposes the computational domain into overlapping LB and NS domains. We point out that the weak compressibility of LB can have a major impact on the coupled system. Although very good agreement is found for Couette scenarios, this is not achieved to same extent in Taylor–Green flows.