Experimental study of non-Newtonian fluid flow inside the corrugated tube inserted with typical and V-cut twisted tapes

Abstract

In present paper has been investigated heat transfer and friction factor characteristics of non-Newtonian base fluid flow through corrugated tube that equipped with various twisted tapes (typical twisted tape (TT) and V-cut twisted tape (VTT)) under constant heat flux density. Base fluid was 0.2 wt.%. carboxymethyl cellulose (CMC) solution, according to the rheological study, the base fluid exhibited pseudoplastic (shear thinning) behavior. The experiments are performed in Reynolds number from 2400 to 6800 with two types of twisted tapes (TT and VTT) and with different twisted ratios (y = 4.5 and 6.07) and three different combinations of depth and width ratios (DR = 0.5 and WR = 0.285, DR = 0.5 and WR = 0.5, DR = 0.285 and WR = 0.5) of twisted tapes. For all experiments with increasing Reynolds number, the Nusselt number increased in while the friction factor decreased and also the maximum thermal performance factor of 1.59 achieved with the use of the VTT with (DR = 0.5 and WR = 0.285) at a twist ratio of 4.5 and Reynolds number of 2400. The new empirical correlations proposed to predict the Nusselt number, friction factor for non-Newtonian fluid flow and compared with experimental data. The results showed that satisfactory agreement between the present correlations and obtained experimental data.