Abstract
This research aims to investigate the effects of variable external magnetic fields on natural convection of a ferrofluid filled in a partially layered porous cavity containing a hot sinusoidal wave rod. The porous layer is located on the right half of the cavity. Horizontal walls of the cavity are adiabatic and the side walls are kept at a constant cold temperature, T-c. Incompressible smoothed particle hydrodynamics (ISPH) method was used to solve the governing partial differential equations with related boundary conditions. In the current scheme of ISPH method, the renormalization kernel function is used for the boundary treatment. The novelty of this work is the suitable choice of the wavy rod inside a cavity with including a variable magnetic field. Numerical analysis has been carried out for different cases of the wavy rod including/excluding cold circular cylinders inside the cavity. Wide ranges of Hartmann number (0 <= Ha <= 20), magnetic field parameter (0 <= M-f <= 1), Darcy parameter (10(-5) <= Da <= 10(-2)), phase deviation (0 <= lambda <= pi), wave amplitude (0.1 <= A <= 0.4), wavelength (0.2 <= B <= 1) and nanoparticle volume fraction (0 <= phi <= 0.05) were considered. It has been found that the variation on the shape of hot wavy rod changes the heat transfer and flow intensity. The magnetic field parameters reduce the flow intensity. The cold circular cylinders became strong blockages for the temperature and streamlines distributions inside a cavity. The porous layer at low Darcy parameter run as a resistance force for heat transfer and fluid flow in a porous area. ISPH method presented a well performance on simulation of the variable external magnetic field sources with a complex geometry of a wavy rod inside a cavity. (c) 2019 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).