Numerical Simulation Of Fluid Flow And Heat Transfer In Nanometer Fluid Based On Lattice Boltzmann Method

Revolving around lattice Boltzmann method, this paper probed into the flow and heattransfer model based on lattice Boltzmann method. This method is a kind of mesoscopiclevel of numerical simulation methods, from the perspective of molecular discrete kinetictheory and statistics in order to study the fluid flow and heat transfer mechanism.Along the Boltzmann equation is firstly to the Boltzmann-BGK equation to latticeBoltzmann equation, boundary processing format this leads the theory of lattice Boltzmannmethod is introduced and derived in detail, which clearly introduce the method when usinglattice Boltzmann method for simulation calculation, need according to known boundaryconditions, macro to determine boundary nodes distribution function. In view of the specificphysical problems at the same time, and accuracy requirements to determine an appropriateboundary processing format.In this paper the author discussed the theory of isothermal models and not isothermalmodel based on the lattice Boltzmann method, and advanced the coupled double distributionfunction model based on Boussineq hypothesis. Based on the above model, this paper builtthe modeling and simulation of the lid driven flow and natural convection problems. Theresults of numerical calculation analysis of the calculated results are compared withtraditional method, and found that the results have good consistency between the two, thusproving the validity and the correctness of the method and procedure.In this paper, the author established a kind of nanofluids with the introduction of nanoparticles in a liquid by gravity, buoyancy lift, intermolecular potential, drag force and brownand white, which is based thermal lattice Boltzmann method of the multi-composition. Themethod simulated the nano tube of fluid flow and heat transfer characteristics and he nanofluid transport parameters. Under different Reynolds number, this paper revealed the heattransfer characteristics of nano particles, which affected by the microscopic stress. From thesimulation results of this paper, we could found that the temperature distribution ofnanofluids is non-uniform distribution characteristics because of the existence ofmicroscopic movement. Under different nano particles volume share, through the simulationresults, can be found, as nano particles share volume rising, the heat transfer coefficient ofnanofluids has been significantly improved. Comparing with pure water, the volume is0.1%of the average convective heat transfer coefficient of nanofluids increase by around5%, asthe volume of share increase, volume share of1%and2%of the average convective heat transfer coefficient of nanofluids increases by10%and17%. Through the contrast abovedata, we can prove that nanofluids can strengthen the effect of the convective heat transfervery well.