TY - JOUR
TI - The study of natural convection heat transfer of nanofluids in a partially porous cavity based on Lattice Boltzmann Method
AU - Yao Shouguang
AU - Huang Tao
AU - Zeng Jianbang
AU - Duan Luobin
AU - Zhao Kai
JN - Thermal Science
PY - 2019
VL - 23
IS - 2
SP - 1003
EP - 1015
PT - Article
AB - This article used the Lattice Boltzmann Method (LBM)to study the heat  transmission of natural convective of nanofluids in a two-dimensional square  cavity partially filled with porous medium. The nanoparticles volume  fraction of Al2O3, Cu and SiO2 were 0.5%, 1%, 1.5%, 2%, 3% and 4%, which were  mixed with water and 70% of ethylene glycol aqueous solution as the base  fluid, and made up six kinds of nanofluids as the research object. Using  nanofluids coupled double distribution LBM model, this paper studied the  rules of natural convection heat transfer of different nanofluids with the  changing of Rayleigh number and the concentration of the nanoparticles in  the two-dimensional square cavity partially filled with porous medium. The  results showed that the average Nusselt number of the hot wall will increase  with the increase of Ra number, and under different heat transfer  conditions, there are two different critical Rayleigh numbers. In the case  of different concentrations of the same concentration, the critical Rayleigh  number is about 105, when Ra > Rac, the average Nusselt number of water is  higher; when Ra < Rac, the average Nusselt number of, the average Nusselt  number of ethylene glycol is higher. In the case of different concentrations  of same particles, the critical Rayleigh number is between 105 and 106,  there was also a crtical Rayleigh number( ' cRa =105) ,when the Ra < ' cRa ,  the average Nusselt number of the hot wall will increase with the increasing  of concentration; when the Ra > ' cRa , there is a slight decreasing in the  average Nusselt number with the increasing of concentration. The crtical  Rayleigh number of water as the base fluid is smaller than that of ethylene  glycol as the base fluid.