In this paper,a lattice Boltzmann BGK(LBGK)model is proposed for simulating incompressible axisymmetric flows.Unlike other existing axisymmetric lattice Boltzmann models,the present LBGK model can eliminate the compre...In this paper,a lattice Boltzmann BGK(LBGK)model is proposed for simulating incompressible axisymmetric flows.Unlike other existing axisymmetric lattice Boltzmann models,the present LBGK model can eliminate the compressible effects only with the smallMach number limit.Furthermore the source terms of themodel are simple and contain no velocity gradients.Through the Chapman-Enskog expansion,the macroscopic equations for incompressible axisymmetric flows can be exactly recovered fromthe present LBGKmodel.Numerical simulations of theHagen-Poiseuille flow,the pulsatile Womersley flow,the flow over a sphere,and the swirling flow in a closed cylindrical cavity are performed.The results agree well with the analytic solutions and the existing numerical or experimental data reported in some previous studies.展开更多
Lattice Boltzmann Method is recently developed within numerical schemes for simulating a variety of physical systems. In this paper a new lattice Bhatnagar-Gross-Krook (LBGK) model for two-dimensional incompressible m...Lattice Boltzmann Method is recently developed within numerical schemes for simulating a variety of physical systems. In this paper a new lattice Bhatnagar-Gross-Krook (LBGK) model for two-dimensional incompressible magnetohydrodynamics (IMHD) is presented. The model is an extension of a hydrodynamics lattice BGK model with 9 velocities on a square lattice, resulting in a model with 17 velocities. Most of the existing LBGK models for MHD can be viewed as compressible schemes to simulate incompressible flows. The compressible effect might lead to some undesirable errors in numerical simulations. In our model the compressible effect has been overcome successfully. The model is then applied to the Hartmann flow, giving reasonable results.展开更多
基金One of authors(T.Zhang)is grateful to Liang Wang for useful discussions.This work is financially supported by the National Basic Research Program of China(Grant No.2011CB707305)the National Natural Science Foundation of China(Grant Nos.51006040 and 51006039)the Fundamental Research Funds for the Central Universities,Hust(Grant Nos.2010MS131 and 2010JC005).
文摘In this paper,a lattice Boltzmann BGK(LBGK)model is proposed for simulating incompressible axisymmetric flows.Unlike other existing axisymmetric lattice Boltzmann models,the present LBGK model can eliminate the compressible effects only with the smallMach number limit.Furthermore the source terms of themodel are simple and contain no velocity gradients.Through the Chapman-Enskog expansion,the macroscopic equations for incompressible axisymmetric flows can be exactly recovered fromthe present LBGKmodel.Numerical simulations of theHagen-Poiseuille flow,the pulsatile Womersley flow,the flow over a sphere,and the swirling flow in a closed cylindrical cavity are performed.The results agree well with the analytic solutions and the existing numerical or experimental data reported in some previous studies.
文摘Lattice Boltzmann Method is recently developed within numerical schemes for simulating a variety of physical systems. In this paper a new lattice Bhatnagar-Gross-Krook (LBGK) model for two-dimensional incompressible magnetohydrodynamics (IMHD) is presented. The model is an extension of a hydrodynamics lattice BGK model with 9 velocities on a square lattice, resulting in a model with 17 velocities. Most of the existing LBGK models for MHD can be viewed as compressible schemes to simulate incompressible flows. The compressible effect might lead to some undesirable errors in numerical simulations. In our model the compressible effect has been overcome successfully. The model is then applied to the Hartmann flow, giving reasonable results.
