In this paper, a method that combines the characteristic-based split finite element method（CBS-FEM） and the direct forcing immersed boundary（IB） method is proposed for the simulation of incompressible viscous flow...In this paper, a method that combines the characteristic-based split finite element method（CBS-FEM） and the direct forcing immersed boundary（IB） method is proposed for the simulation of incompressible viscous flows. The structured triangular meshes without regarding the location of the physical boundary of the body is adopted to solve the flow, and the no-slip boundary condition is imposed on the interface. In order to improve the computational efficiency, a grid stretching strategy for the background structured triangular meshes is adopted. The obtained results agree very well with the previous numerical and experimental data. The order of the numerical accuracy is shown to be between 1 and 2. Moreover, the accuracy control by adjusting the number density of the mark points purely at certain stages is explored, and a second power law is obtained. The numerical experiments for the flow around a cylinder behind a backward-facing step show that the location of the cylinder can affect the sizes and the shapes of the corner eddy and the main recirculation region. The proposed method can be applied further to the fluid dynamics with complex geometries, moving boundaries, fluid-structure interactions, etc..展开更多
基金Project supported by the National High Technology Re-search and Development Program of China(863 Program,Grant No.2012AA011803)the National Natural Scientific Foundation of China(Grant No.11172241)the University Foundation for Fundamental Research of NPU(Grant No.JCY-20130121)
文摘In this paper, a method that combines the characteristic-based split finite element method（CBS-FEM） and the direct forcing immersed boundary（IB） method is proposed for the simulation of incompressible viscous flows. The structured triangular meshes without regarding the location of the physical boundary of the body is adopted to solve the flow, and the no-slip boundary condition is imposed on the interface. In order to improve the computational efficiency, a grid stretching strategy for the background structured triangular meshes is adopted. The obtained results agree very well with the previous numerical and experimental data. The order of the numerical accuracy is shown to be between 1 and 2. Moreover, the accuracy control by adjusting the number density of the mark points purely at certain stages is explored, and a second power law is obtained. The numerical experiments for the flow around a cylinder behind a backward-facing step show that the location of the cylinder can affect the sizes and the shapes of the corner eddy and the main recirculation region. The proposed method can be applied further to the fluid dynamics with complex geometries, moving boundaries, fluid-structure interactions, etc..
