A new lattice Bhatnagar-Gross-Krook （LBGK） model for a class of the generalized Burgers equations is proposed. It is a general LBGK model for nonlinear Burgers equations with source term in arbitrary dimensional spa...A new lattice Bhatnagar-Gross-Krook （LBGK） model for a class of the generalized Burgers equations is proposed. It is a general LBGK model for nonlinear Burgers equations with source term in arbitrary dimensional space. The linear stability of the model is also studied. The model is numerically tested for three problems in different dimensional space, and the numerical results are compared with either analytic solutions or numerical results obtained by other methods. Satisfactory results are obtained by the numerical simulations.展开更多
In this paper, an implicit scheme (also called the θ method) was proposed for the Lattice Bhatager-Gross-Krook (LBGK) model simulating incompressible flows. The new parameter θ made the model more flexible. Through ...In this paper, an implicit scheme (also called the θ method) was proposed for the Lattice Bhatager-Gross-Krook (LBGK) model simulating incompressible flows. The new parameter θ made the model more flexible. Through the Chapman-Enskog procedure the impressible Navie-Stokes equations could be recovered with the coupled kinetic viscosity. Boundary conditions were treated briefly and it kept the numerical accuracy of the Lattice Boltzmann Method (LBM). The two-dimensional Poiseuille flow was simulated with different values of the parameters. It is found that the numerical accuracy and stability of the implicit scheme can be improved if some adaptable parameters are chosen.展开更多
In recent years, the Lattice Boltzmann Method (LBM) has developed into an alternative and promising numerical scheme for simulating fluid flows and modeling physics in fluids. In order to propose LBM for high Reynolds...In recent years, the Lattice Boltzmann Method (LBM) has developed into an alternative and promising numerical scheme for simulating fluid flows and modeling physics in fluids. In order to propose LBM for high Reynolds number fluid flow applications, a subgrid turbulence model for LBM was introduced based on standard Smagorinsky subgrid model and Lattice Bhatnagar-Gross-Krook (LBGK) model. The subgrid LBGK model was subsequently used to simulate the two-dimensional driven cavity flow at high Reynolds numbers. The simulation results including distribution of stream lines, dimensionless velocities distribution, values of stream function, as well as location of vertex center, were compared with benchmark solutions, with satisfactory agreements.展开更多
We report on our study of the static and dynamic wetting property of hydrophobic surfaces with micro-and dual micro/nano-scale structures.Simulations based on the lattice Boltzmann method showed that the apparent cont...We report on our study of the static and dynamic wetting property of hydrophobic surfaces with micro-and dual micro/nano-scale structures.Simulations based on the lattice Boltzmann method showed that the apparent contact angle of water droplets on hy-drophobic surfaces with micro-scale structures increases as solid area decreases,whereas dual micro/nano-scale structures not only increase surface hydrophobicity but also greatly stabilize the Cassie state of droplets.Droplets falling on a superhydrophobic surface distort and,depending of free energy,sometimes bounced on the surface before finally adhering to the surface.These phenomena are in agreement with experimental observations.Simulated results also show that micro/nano-scale surface structures can increase droplet rebound height,which depends on static apparent contact angle.展开更多
基金Project supported by the National Natural Science Foundation of China （Grant Nos 70271069 and 60073044）.
文摘A new lattice Bhatnagar-Gross-Krook （LBGK） model for a class of the generalized Burgers equations is proposed. It is a general LBGK model for nonlinear Burgers equations with source term in arbitrary dimensional space. The linear stability of the model is also studied. The model is numerically tested for three problems in different dimensional space, and the numerical results are compared with either analytic solutions or numerical results obtained by other methods. Satisfactory results are obtained by the numerical simulations.
文摘In this paper, an implicit scheme (also called the θ method) was proposed for the Lattice Bhatager-Gross-Krook (LBGK) model simulating incompressible flows. The new parameter θ made the model more flexible. Through the Chapman-Enskog procedure the impressible Navie-Stokes equations could be recovered with the coupled kinetic viscosity. Boundary conditions were treated briefly and it kept the numerical accuracy of the Lattice Boltzmann Method (LBM). The two-dimensional Poiseuille flow was simulated with different values of the parameters. It is found that the numerical accuracy and stability of the implicit scheme can be improved if some adaptable parameters are chosen.
文摘In recent years, the Lattice Boltzmann Method (LBM) has developed into an alternative and promising numerical scheme for simulating fluid flows and modeling physics in fluids. In order to propose LBM for high Reynolds number fluid flow applications, a subgrid turbulence model for LBM was introduced based on standard Smagorinsky subgrid model and Lattice Bhatnagar-Gross-Krook (LBGK) model. The subgrid LBGK model was subsequently used to simulate the two-dimensional driven cavity flow at high Reynolds numbers. The simulation results including distribution of stream lines, dimensionless velocities distribution, values of stream function, as well as location of vertex center, were compared with benchmark solutions, with satisfactory agreements.
基金the National Natural Science Foundation of China (10872106 and 11072126)
文摘We report on our study of the static and dynamic wetting property of hydrophobic surfaces with micro-and dual micro/nano-scale structures.Simulations based on the lattice Boltzmann method showed that the apparent contact angle of water droplets on hy-drophobic surfaces with micro-scale structures increases as solid area decreases,whereas dual micro/nano-scale structures not only increase surface hydrophobicity but also greatly stabilize the Cassie state of droplets.Droplets falling on a superhydrophobic surface distort and,depending of free energy,sometimes bounced on the surface before finally adhering to the surface.These phenomena are in agreement with experimental observations.Simulated results also show that micro/nano-scale surface structures can increase droplet rebound height,which depends on static apparent contact angle.
