Numerical investigation of transient flow-mode transition of laminar natural convection in an inclined enclosure

Abstract The present work is concerned with a numerical investigation of transient laminar natural convection and the associated flow-mode transition in a two-dimensional rectangular enclosure. Navier-Stokes / Boussinesq equations for fluid flow and energy balance are solved by using the SIMPLE-C algorithm. Air of Pr = 0.71 in a differentially heated enclosure of length-to-height aspect ratio As = 4 and at Ra = 5000 is chosen as the flow model to examine the influences of the inclination. Calculations of time accuracy are performed to investigate the transient procedure of the flow-mode transition with increasing or decreasing inclination, lite present results reveal that, at some critical situations, natural convection in inclined enclosures is very sensitive to the change in tilt angle, and the associated heat transfer rates are closely related to the correspondent cellular flow patterns.