Numerical study of natural convection in a porous cavity filled with Fe3O4/Water nanofluid: Heated partially with wavy wall from bottom

Natural convection in a square porous container full of Fe3O4/water nanofluid and having a wavy wall is studied numerically. The wavy wall is hot, whereas the remainder of the bottom surface are adiabatic. The left and right sides are thermally insulated; however, the top wall is cold. For modelling porous media with nanofluid, the Darcy-Brinkman-Forchheimer model was considered. The governing equations have been solved by using finite element methods. The non-dimensional parameters which were used in this work are Rayleigh number (Ra=104 to106), Darcy number (Da=10−2), number of waves (N=1, 3, 5, and 7), porosity (ε=0.6), volume fraction (ϕ=0.05), and Prandtl number (Pr=7.2). Heat transfer rises as the Ra increases, but it decreases as the number of waves increases. It has been concluded at Ra=106, and N=1 the enhancement of heat transfer is maximum and the maximum Nusselt number on the wavy wall is equal to 6.643 while the minimum Nusselt number is 0.1336 at Ra=103, and N=7.