By employing the finite element method, thermophoresis and Brownian diffusion are studied numeri-cally relating to the natural convection in a wavy cavity that is filled with an Al2O3-water nanofluid pos-sessing a central heat-conducting solid block that is influenced by the local heater located on the bottomwall. An isothermal condition is established in the two wavy vertical walls, while adiabatic condition isfor the top horizontal wall. Partial heating is applied to the bottom of the horizontal wall, while theremaining part remains in the adiabatic condition. Empirical correlations are employed for the thermalconductivity and dynamic viscosity of the nanofluid. The number of oscillations (16N<4), Rayleighnumber (1036Ra<106), nanoparticles volume fraction (06/<0:04) and dimensionless length ofthe bottom heater (0:26H60:8) govern the parameters in this study. The grid independency test, aswell as experimental and numerical data from other published works, was employed to validate thedeveloped computational code comprehensively. Based on the obtained results, it was found that theheat transfer inside the cavity is enhanced by introducing nanoparticles as well as a selection of optimalnumber of oscillations.
Advanced powder technology. 2019. Vol. 30, № 2. P. 399-414
Language
eng
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Механико-математический факультет
Numerical investigation of natural convection of Al2O3-water nanofluid in a wavy cavity with conductive inner block using Buongiorno's two-phase model