the effect of various conductivity and viscosity models considering brownian motion on nanofluids mixed convection flow and heat transfer

In this paper the effect of using various models for conductivity and viscosity considering brownian motion ofnanoparticles is investigated. this study is numerically conducted inside a cavity full of water-al2o3 nanofluid at the case of mixedconvection heat transfer. the effect of some parameters such as the nanoparticle volume fraction, rayleigh, richardson and reynoldsnumbers has been examined. the governing equations with specified boundary conditions has been solved using finite volume method.a computer code has been prepared for this purpose. the results are presented in form of stream functions, isotherms, nusselt numberand the flow power with and without the brownian motion taken into consideration. the results show that for all the applied models thestream functions and isotherm have approximately same patterns and no considerable difference has been observed. in all the studiedmodels when considering the brownian motion, the average nusselt number is higher than not taking this effect into account. themodels of koo-kleinstreuer and li-kleinstreuer give almost same values for the maximum stream function and average nusseltnumber. it is also true about the models of vajjha-das and xiao et al.