Active chimney effect using heated porous layers: optimum heat transfer Abdelhak Mehiris, Djamel-Edine Ameziani, Omar Rahli, Khadija Bouhadef and Rachid Bennacer Eur. Phys. J. Appl. Phys., 78 3 (2017) 34807 Published online: 12 May 2017 DOI: 10.1051/epjap/2017160398