Lattice Boltzmann Simulation Of The Homogeneous Isotropic Turbulence

In recent years, lattice Boltzmann method is a new mesoscopic simulation approach of complex flow. How to apply the numerical simulation of turbulence theory and practice is the issue concerned importantly. The initialization and homogeneous isotropic turbulence simulation studies which are involved with lattice Boltzmann method simulation of turbulence are carried out in the paper, as follows:First of all, simulate the two simple models such as two-dimensional Taylor-Green vortex and three-dimensional Beltrami flow with analytical solution with lattice Boltzmann method. Calculating the pressure field and the total energy in the different conditions, discuss the initialization processing, fluid viscosity, as well as a number of computational grid for the three conditions in detail. Summarize the impact of simulation results, and show that: the initial pressure values are zero, the time reaching the steady state is longer .In the initial time the pressure fluctuates obviously. When the pressure comes to steady state, the flow field pressure has the smaller error between the real pressure fields. But the pressure effects the total kinetic energy slightly and the fluctuations in total kinetic energy are smaller with the smaller error between the real fluid; The smaller Viscous coefficient takes the less energy loss when the results come to be stable with the real flow with lattice Boltzmann method, and the error between them is smaller; And the numbers of grid of the computing region directly affect the results. When the number of each coordinate grid divided is more than 8, the more the number is, the more accurate the results are. But when the number of each grid coordinates is close to 8, lattice Boltzmann method has been distortion of the results.With the solution of the initialization, fluid viscosity, and the number of computational grid, which are discussed, finally apply lattice Boltzmann method in the isotropic turbulence to carry out the direct numerical simulation. Compare the velocity field and vorticity field at different moments and show that the lattice Boltzmann method is a viable method of numerical simulation of turbulence.