3D Magneto-buoyancy-thermocapillary convection of CNT-water nanofluid in the presence of a magnetic field

Anumerical study is performed to investigate the effects of adding Carbon Nano Tube (CNT) and applying a magnetic field in two directions (vertical and horizontal) on the 3D-thermo-capillary natural convection. The cavity is differentially heated with a free upper surface. Governing equations are solved using the finite volume method. Results are presented in term of flow structure, temperature field and rate of heat transfer. In fact, results revealed that the flow structure and heat transfer rate are considerably affected by the magnitude and the direction of the magnetic field, the presence of thermocapillary forces and by increasing nanoparticles volume fraction. In opposition, the increase of the magnetic field magnitude leads to the control the flow causing flow stabilization by merging vortexes and reducing heat transfer rate. © 2020 by the authors

Numerical investigation of combined buoyancy-thermocapillary convection and entropy generation in 3D cavity filled with Al2O3 nanofluid

Heat transfer, fluid flow and entropy generation due to combined buoyancy and thermocapillary forces in a 3D differentially heated enclosure containing Al2O3 nanofluid are carried out for different Marangoni numbers and different nanoparticles concentrations. The vector potential-vorticity formalism and the finite volume method are used respectively to formulate and to solve the governing equations and calculations were performed for Marangoni number from −103 to 103, volume fraction of nanoparticles from 0 to 0.2 and for a fixed Rayleigh number at 105. An intensification of the flow and an increase in heat transfer and of total entropy generation occur with the increase in nanoparticles volume fraction for all Marangoni numbers