The effect of ribs spacing on heat transfer in rectangular channels under the effect of different types of heat flux in the Presence of a nanofluids

Abstract

In this study, numerical computations of the influence of adding ribs in a rectangular channel on the forced convection heat transfer and laminar fluid flow characteristics has been carried out. The analysis was carried out by using the finite element method to solve the dimensionless governing equations for two-dimensional channel with 80 mm height and 2000 mm length at the Reynolds number of (10, 100, and 500), rib height e=8mm with different aspect ratios (AR =2.5, 3.125, 3.75, 4.375, and 5). Also, the study compared two cases of investigations with and without nanofluid (Water/ TiO2) at the volume fractions of nanoparticles of 0, 2 and 4%. The results concluded that, for a certain arrangements, the use of extended surfaces within a rectangular channel can significantly enhance the rate of heat transfer and when the aspect ratios decreases, the Nusselt number increased. However, the existence of ribs within channel in case of constant heat flux can cause a significant improvement of heat transfer compared to that in the corresponding channel under the variable heat flux.

The influence of micro-channel shape filled by nanofluid on heat transfer characteristics: Numerical and experimental study

“…The volume fractions used are 0.1%, 0.2%, and 0.3% respectively. Table 2 presents the thermo-physical characteristics of nanoparticles [27,28].…”

Experimental and numerical study of forced convictive heat transfer in a horizontal circular pipe with varying angles ribs

“…Nakhchi and Esfahani [40] conducted a numerical investigation into the increase of convective heat transfer in a circular pipe utilizing several rib shapes, including flat conical, right angle, and variations in the height, width, and pitch of the rib. Sadiq and Hamza [41] looked the effect of distance between the ribs on heat transfer inside a rectangular duct with constant and variable heat flow, as well as with and without Nano fluids. Wang et al [42] examined numerically the enhancement of heat transfer in circular pipe using trapezoid ribs and smooth pipe at constant Reynolds number.…”