Nusselt number and friction factor behaviour of circular wavy transverse ribs artificially roughened solar air heater

Abstract

The present study deals about the fluid flow and heat transfer behaviours of circular wavy wall transverse rib artificially roughened SAH. The circular wavy ribs are used in the solar air (SAH) heater with different undulation (N) and constant amplitude (A) below absorbing plate at testing zone for the present numerical investigation. Heat transfer behaviour varies about number of undulation with the intention that the optimum undulation of circular wavy wall transverse rib is necessary for better performance of SAH. The FLUENT v 14.5 is used to solve the governing equations (mass, momentum and energy). The RNG (k- ϵ) model is utilized to capture the turbulent effects and also the SIMPLE algorithm is used to couple the pressure and velocity. The geometrical parameter, pitch (p/e) ranges from 7.14 to 14.28 and relative roughened height (e/D) ranges from 0.021 to 0.042 are taken. The Reynolds numbers (Re) is varied between 3800 and 18000 for the constant heat (q) flux of plate 1000 W/m2. The results, Nusselt number (Nur/Nus) enhancement, and friction (fr/fs) factor performance are presented. © 2019 IOP Publishing Ltd. All rights reserved.