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
According to modeling principle that a model must be more accurate ifincluding more flow information, and based on the Cauchy-Helmholtz theorem and the Smagorinskymodel, a second-order dynamic model with double dynami...According to modeling principle that a model must be more accurate ifincluding more flow information, and based on the Cauchy-Helmholtz theorem and the Smagorinskymodel, a second-order dynamic model with double dynamic coefficients was proposed by applyingdimension analyses. The Subgrid-Scale (SGS) stress is a function of both strain-rate tensor androtation-rate tensor. The SIMPLEC algorithm and staggering grid system was applied to give thesolution of the discretized governing equations, and for the turbulent flow through a 90° bend, thedistributions of velocity and pressure were achieved. The comparison between experimental data andsimulation results at a Reynolds- number 40000 shows a good agreement and implies that this model ispracticable and credible.展开更多
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.
文摘According to modeling principle that a model must be more accurate ifincluding more flow information, and based on the Cauchy-Helmholtz theorem and the Smagorinskymodel, a second-order dynamic model with double dynamic coefficients was proposed by applyingdimension analyses. The Subgrid-Scale (SGS) stress is a function of both strain-rate tensor androtation-rate tensor. The SIMPLEC algorithm and staggering grid system was applied to give thesolution of the discretized governing equations, and for the turbulent flow through a 90° bend, thedistributions of velocity and pressure were achieved. The comparison between experimental data andsimulation results at a Reynolds- number 40000 shows a good agreement and implies that this model ispracticable and credible.
