A Quadtree-gridding LBM with Immersed Boundary for Two-dimension Viscous Flows

[摘要] An un-uniform quadtree grids lattice Boltzmann method (LBM) with immersed boundary is presented in this paper. In overlapping for different level grids, temporal and spatial interpolation are necessary to ensure the continuity of physical quantity. In order to take advantage of the equation for temporal and spatial step in the same level grids, equal interval interpolation, which is simple to apply to any refined boundary grids in the LBM, is adopted in temporal and spatial aspects to obtain second-order accuracy. The velocity correction, which can guarantee more preferably no-slip boundary condition than the direct forcing method and the momentum exchange method in the traditional immersed-boundary LBM, is used for solid boundary to make the best of Cartesian grid. In present quadtree-gridding immersed-boundary LBM, large eddy simulation (LES) is adopted to simulate the flows over obstacle in higher Reynolds number (Re). The incompressible viscous flows over circular cylinder are carried out, and a great agreement is obtained.

[发布机构] Chengdu Aircraft Industrial (Group) CO.LTD., Chengdu; 610092, China^1

[效力级别] 无线电电子学

[关键词] Immersed boundary;Incompressible viscous flows;Lattice boltzmann methods (LBM);Momentum exchange;No-slip boundary conditions;Physical quantities;Second-order accuracy;Temporal and spatial