Characterization of the Effect of Corrugation Angles on Hydrodynamic and Heat Transfer Performance of Four-Start Spiral Tubes

Abstract

A series of four-start spirally corrugated tubes has been subjected to heat transfer and hydrodynamic testing in a double-pipe heat exchanger. The study has been focused on the non-symmetric nature of the corrugation angles along the longitudinal direction. Both friction factors and heat transfer coefficients inside the tubes have been correlated against various process parameters. It can be shown that by altering the internal non-symmetric wavy shapes of the tubes, one is able to manipulate heat transfer and friction characteristics. The experimental results have been compared with some popular correlation models developed previously for both friction and heat transfer for corrugated tubes. Considerable differences between the experimental results and the predictions made using the existing correlations have been found and the probable causes have been discussed. Performance evaluation criteria are presented using the standard constant power criterion. A neural network modeling approach has been taken so that, based on the limited data, one can generate the contour showing the effect of corrugation angle on heat transfer coefficient for geometry optimization purposes.

Correlating heat transfer and friction in helically-finned tubes using artificial neural networks

“…However, the focus was only on the shape of the corrugation and not the helix angle. Chen et al [22] tested tubes with four starts, a similar pitch ($9 mm), diameter ($18.9 mm), ridge height ($2.2 mm), and helix angle ($61°) but different corrugation shapes. The shape of the corrugation was quantified in terms of angles a 0 and a 00 as shown in Fig.…”

“…Scalabrin and Piazza [21] applied neural networks to analyze heat transfer from tubes with supercritical carbon dioxide. Chen et al [22] analyzed spirally corrugated tubes in terms of ANNs. However, the focus was only on the shape of the corrugation and not the helix angle.…”

A Review on the Heat-Transfer Performance and Pressure-Drop Characteristics of Various Enhanced Tubes

“…Chen et al 12 experimentally investigated the heat-transfer and friction characteristics of fourstart spirally corrugated tubes. A double-pipe counter°ow heat exchanger was used as the test section.…”

Experimental and Numerical Investigation of the Pressure Drop and Heat Transfer Coefficient in Corrugated Tubes

“…Their potential to increase the heat transfer rate was proven for spirally corrugated tubes under turbulent gas flow conditions. Corrugated tubes were primarily investigated with respect to liquid-to-liquid heat transfer in the Prandtl range of 2.5 < Pr < 100 [4][5][6][7][8]. Experimental studies by Barba et al [9] and Rozzi et al [10] concentrated on the use of corrugated tubes in the food industry with juices and non-Newton fluids.…”