MHD natural convection in a nanofluid-filled open enclosure with a sinusoidal boundary condition

• Lattice Boltzmann method is applied to the problem.
• The phase deviation effect is studied.
• The effects of Hartmann number, Rayleigh number and solid volume fraction are examined.

This paper examines the natural convection in an open cavity with a sinusoidal thermal boundary condition. The cavity is filled with a water–Al2O3 nanofluid and subjected to a magnetic field. Lattice Boltzmann method (LBM) is applied to solve the coupled equations of flow and temperature fields. This study has been carried out for the pertinent parameters in the following ranges: Rayleigh number of the base fluid, Ra = 103 to 106, Hartmann number varied from Ha = 0 to 60, the phase deviation (γ = 0, π/4, π/2, 3π/4 and π) and the solid volume fraction of nanoparticles between ϕ = 0 and 6%. Results show that the heat transfer rate decreases with the increase of Hartmann number and increases with the rise of Rayleigh number. At Ha = 30 and Ra = 103 to 105, for all phase deviations the addition of nanoparticles increases heat transfer rate. Also, at low Rayleigh number (Ra ≤ 104) the highest heat transfer rate is obtained for γ = π/2.

Figure optionsDownload high-quality image (469 K)Download as PowerPoint slide