New methodology for the walls design in buildings by numerical simulation of the thermal convection Elhadj Benachour, Belkacem Draoui, Bachir Imine, Khadidja Asnoune and Elmir Mohamed EPJ Web Conf., 143 (2017) 02007 Published online: 12 May 2017 DOI: 10.1051/epjconf/201714302007