Numerical Investigation of a Solar Air Heater (SAH) with Triangular Artificial Roughness Having a Curved Top Corner

Abstract

In the present study, numerical investigation of two-dimensional incompressible air flow through a solar air heater (SAH) with a triangular artificial roughness having a curved top corner is performed using ANSYS Fluent 15.0 based finite volume method. The geometrical parameters of the triangular ribs having a curved top corner such as the roughness height ratio (e/D = 0.021, 0.03 and 0.042) and the roughness pitch ratio (p/e =7.14, 10.70, 14.28 and 17.86) have been investigated for a varied Reynolds number between 3800 to 18000. Flow and energy governing equations were solved with the accosiation of two transport equation for the turbulence kinetic energy k and the dissipation rate ɛ. The RNG k-ε turbulent model have been selected to be the more appropriate turbulence model for the present study. Results indicates that the values of Nusselt number and friction factor strongly depend on the roughness relative height e/D, relative pitch p/e and the value of Re number. The best solar air heater performance could be obtained for e/D=0.042 and p/e=7.14.

Two‐dimensional‐numerical investigation on the influence of first rib distance from the entrance of channel on Nusselt number and pressure drop

“…The flow and heat transfer characteristics of the channel were found to be affected by the placement of the first rib from the channel entrance. The Nusselt number is also found to vary with pitch and rib thickness 10 . The Nusselt number was maximum for a pitch of 5 mm, for all the three rib designs.…”

“…The Nusselt number is also found to vary with pitch and rib thickness. 10 The Nusselt number was maximum for a pitch of 5 mm, for all the three rib designs. When ribs are incorporated in a channel, the increase in heat transfer is frequently accompanied by an increase in pressure drop and thus increases the pumping power requirement.…”

Effect of Steps Height and Glass Cover Angle on Heat Transfer Performance for Solar Distillation: Numerical Study

“…In addition, most and less variation of the heat transfer coefficient obtained for the step height of 5.5cm with hc=4.04 W/m 2 K, with 39⁒ increase and for the step height of 1cm with hc=2.18 W/m 2 K, with 24⁒ decrease, respectively. doi: 10.5829/ije.2022. 35…”

“…The sunlight can be converted into directly for thermal objectives, e.g. in solar chimney [8,9], air heating [10,11], solar dryers [12,13], solar water heaters [14][15][16]. Another interesting applications of the solar heat is solar desalination, which is studied in this study.…”

Numerical investigation on location of protrusions and dimples during slot jet impingement on a concave surface using hybrid ANN–GA

“…Lo and Liu 5 suggested the incorporation of uniformly scattered roughness structures, like, pin fins, ribs, or dimples, for improvement in heat transfer. Zina and Dewan 6 numerically investigated the performance of triangular ribs on a solar air heater. They obtained an increase in Nusselt number with the increase of pitch between ribs and depth of rib.…”