TY - JFULL AU - M. Yousaf and S. Usman PY - 2015/12/ TI - Effects of Roughness Elements on Heat Transfer during Natural Convection T2 - International Journal of Chemical and Molecular Engineering SP - 1286 EP - 1292 VL - 9 SN - 1307-6892 UR - https://publications.waset.org/pdf/10002713 PU - World Academy of Science, Engineering and Technology NX - Open Science Index 107, 2015 N2 - 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. ER -