Influences of submerged V-broken rib geometry on the hydrothermal performance of vortex and engulfment flow regimes within a T-channel

Abstract

The current research presents a three-dimensional numerical study of detailed hydrothermal performance in a T-channel fitted with staggered V-broken ribs under laminar vortex and engulfment flow regimes (Re = 50 to 250) using CFD software tool FLUENT. Comprehensive parametrical investigations are executed to probe the influences arising from the geometrical parameters alterations of the V-broken ribs on the flow field and convective heat transfer characteristics in T-channel. A set of geometrical parameters involving, the orientation rib angles (θ = 30°, 45°, 60°), the pitch-to-outlet-channel width ratio (p/W_o = 1, 1.5, 2), the length-to-outlet-channel width ratio (l/W_o = 0.5, 0.75, 1), the height-to-outlet-channel height ratio (h/H_o = 0.2, 0.3, 0.4), and the staggered inclined rib arrangements (forward, backward, and mixed), are considered. With regard to all examined geometrical parameters, the presence of staggered V-broken ribs consistently enhances fluid mixing and convective heat transfer performance as compared with that without ribs. In addition, the findings illustrate that the V-broken ribs mounted on the bottom wall of the T-channel have approximately the same PEC at 45° and 60° orientation angles with a PEC of 2.23 at Re = 250. At Re = 250, the PEC improves by 40 % and 53 % in comparison to the standard T-channel for the 2 cm and the 4 cm of longitudinal pitch, respectively. Regarding, V-broken rib lengths of 1.5 cm and 1 cm, PEC shows similar trend and eventually reaches double, while the PEC for a 2 cm rib length is smaller than that of 1 and 1.5 cm. The results also exhibit that the smaller rib height of 2 mm gives higher PEC, approximately 2.15, in comparison to 3 mm and 4 mm. Finally, the backward V-broken rib arrangement provides the best PEC of the T-channel, around 2.42.