The present work demonstrates the natural convection of two layers filled the space between inner circular cylinder located within wavy enclosure using finite element scheme. The right layer is filled with Ag nano-fluid while the left layer is filled saturated porous media and the same nanofluid. The governing equations of fluid flow and heat transfer (mass, energy and momentum of the fluid) have been formulated in dimensionless form with related initial and boundary conditions the numerical solution include the subdividing the fluid flow domain to two sets of transport equations. The Darcy-Brinkman model was considered for modeling porous media with nano-fluid. The considered dimensionless parameters are Rayleigh number (106≥Ra≥103), Darcy number (10-1≥Da≥10-5), cylinder's radius (0.4≥R≥0.2), circular cylinder vertical position (+0.2≥δ≥-0.2), the number of undulation (3≥N≥0) and nano-particle volume fraction (0.1≥φ≥0). The nanofluid is combining of Ag solid particle and water as a main fluid. The results were presented according to the stream-lines, isotherms, local and the mean of Nusselt number. The results have demonstrated the increasing in the value of the Rayleigh and Darcy numbers as well as nanofluid volume fraction enhances both fluid flow strength and average of heat transfer. It has been concluded that when the number of undulations N = 1 gives better heat transfers enhancement. It is recommended that for better heat transfer average to move the internal circular cylinder with radius (R = 0.2) vertically downward (δ=-0.2) with undulations' number (N=1).