Sharp-interface immersed boundary lattice Boltzmann method with reduced spurious-pressure oscillations for moving boundaries

摘要

A sharp-interface immersed boundary lattice Boltzmann method (IBLBM) is developed to reduce spuriouspressurenoscillations in moving boundary problems.We adopt a cut-cell-based method, i.e., the partially saturatedncomputational cell method, because the primary cause of spurious-pressure oscillations is the failure to obeynthe geometric conservation law near the boundary in the sharp-interface IBLBM. We modify a sharp-interfacenIBLBM (ghost fluid method) to fit the cut-cell approach. This boundary condition can guarantee the Dirichletnand Neumann boundary conditions for velocity and pressure. Some simulations are shown to test the validity ofnthe method, including a circular cylinder with motions that are at rest, moving, oscillatory, and neutrally buoyant.nThe results illustrate that the method reduces effectively spurious pressure and can simulate moving boundarynproblems, especially when pressure field accuracy is a key concern.