%0 Journal Article %A M. Yousaf and S. Usman %D 2015 %J International Journal of Chemical and Molecular Engineering %B World Academy of Science, Engineering and Technology %I Open Science Index 107, 2015 %T Effects of Roughness Elements on Heat Transfer during Natural Convection %U https://publications.waset.org/pdf/10002713 %V 107 %X The present study focused on the investigation of the effects of roughness elements on heat transfer during natural convection in a rectangular cavity using numerical technique. Roughness elements were introduced on the bottom hot wall with a normalized amplitude (A*/H) of 0.1. Thermal and hydrodynamic behaviors were studied using computational method based on Lattice Boltzmann method (LBM). Numerical studies were performed for a laminar flow in the range of Rayleigh number (Ra) from 103 to 106 for a rectangular cavity of aspect ratio (L/H) 2.0 with a fluid of Prandtl number (Pr) 1.0. The presence of the sinusoidal roughness elements caused a minimum to maximum decrease in the heat transfer as 7% to 17% respectively compared to smooth enclosure. The results are presented for mean Nusselt number (Nu), isotherms and streamlines. %P 1287 - 1292