Abstract

Results of an experimental investigation of heat transfer and flow friction of a generalized power-law fluid in tape generated swirl flow inside a 25.0 mm i.d. circular tube, are presented. In order to reduce excessive pressure drops associated with full width twisted tapes, with less corresponding reduction in heat transfer coefficients, reduced width twisted tapes of widths ranging from 11.0 to 23.8 mm, which are lower than the tube inside diameter are used. Reduced width twisted tape inserts give 18 percent–56 percent lower isothermal friction factors than the full width tapes. Uniform wall temperature Nusselt numbers decrease only slightly by 5 percent–25 percent, for tape widths of 19.7 and 11.0 mm, respectively. Based on the constant pumping power criterion, the tapes of width 19.7 mm perform more or less like full width tapes. Correlations are presented for isothermal and heating friction factors and Nusselt numbers (under uniform wall temperature condition) for a fully developed laminar swirl flow, which are applicable to full width as well as reduced width twisted tapes, using a modified twist ratio as pitch to width ratio of the tape. The reduced width tapes offer 20 percent–50 percent savings in the tape material as compared to the full width tapes. [S0022-1481(00)01401-8]

Issue Section:
Heat Transfer Enhancement
Keywords:
laminar flow, heat transfer, swirling flow, non-Newtonian flow, rheology, Augmentation, Enhancement, Heat Transfer, Laminar, Non-Newtonian, Swirling
Topics:
Flow (Dynamics), Fluids, Friction, Heat transfer, Laminar flow, Pressure drop
1.
Metzner
,
A. B.
,
Vaughn
,
R. D.
, and
Houghton
,
G. L.
,
1957
, “
Heat Transfer to Non-Newtonian Fluids
,”
AIChE. J.
,
3
, p.
92
92
.
2.
Metzner
,
A. B.
, and
Gluck
,
D. G.
,
1960
, “
Heat Transfer to Non-Newtonian Fluids Under Laminar Flow Conditions
,”
Chem. Eng. Sci.
,
12
, pp.
185
–
192
.
3.
Hong
,
S. W.
, and
Bergles
,
A. E.
,
1976
, “
Augmentation of Laminar Flow Heat Transfer in Tubes by Means of Twisted Tape Inserts
,”
ASME J. Heat Transfer
,
98
, pp.
251
–
256
.
4.
Sukhatme, S. P., Gaitonde, U. N., Shindore, C. S., and Kunlolienkar, R. S., 1987, “Forced Convection Heat Transfer to a Viscous Liquid in Laminar Flow in a Tube with a Twisted Tape,” Proceedings of 9th H.M.T. Conference, Banglore, India, pp. B1–B7.
5.
Marner, W. J., and Bergles, A. E., 1978, “Augmentation of Tube Side Laminar Flow Heat Transfer by Means of Twisted Tape Inserts, Static Mixer Inserts and Internally Finned Tubes,” Proceedings of Sixth International Heat Transfer Conference, Toronto, Hemisphere, Washington, D.C., Vol. 2, pp. 583–588.
6.
Shivkumar, C., and Raja Rao, M., 1988, “Compound Augmentation of Laminar Flow Heat Transfer to Generalized Power Law Fluids in Spirally Corrugated Tubes by Means of Twisted Tape Inserts,” ASME Proceedings of National Heat Transfer Conference, Houston, Vol.1, ASME, New York, pp. 685–692.
7.
Dasmahapatra, J. K., and Raja Rao, M., 1991, “Laminar Flow Heat Transfer to Generalized Power Law Fluids Inside Circular Tubes Fitted with Regularly Spaced Twisted Tape Elements for Uniform Wall Temperature Condition” Fundamentals of Heat Transfer in Non-Newtonian Fluids, ASME, New York, pp. 51–58.
8.
Date, A. W., and Singham, J. R., 1972, “Numerical Prediction of Friction and Heat Transfer Characteristics of Fully Developed Laminar Flow in Tubes Containing Twisted Tapes,” ASME Paper No. 72-HT-17.
9.
Du Plessis
,
J. D.
, and
Kroger
,
D. G.
,
1987
, “
Friction Factor Prediction for Fully Developed Laminar Twisted Tape Flow
,”
Int. J. Heat Mass Transf.
,
3
, pp.
509
–
515
.
10.
Shah, R. K., and London, A. L., 1978, “Laminar Flow Forced Convection in Ducts,” Advances in Heat Transfer, Vol. 1, Supplement-1, Academic, New York, pp. 379–381.
11.
Manglik, R. M., and Bergles, A. E., 1987, “A Correlation for Laminar Flow Enhanced Heat Transfer in Uniform Wall Temperature Circular Tubes With Twisted Tape Inserts,” Advances in Enhanced Heat Transfer, Vol. 68, ASME, New York, pp. 19–25.
12.
Zhu
et al.,
1992
, “
Augmentation of Heat Transfer for Viscous Fluids Using the Turbolator
,”
Gaoxiao Huaxue Gongcheng Xuebao
6
, pp.
56
–
61
(Chinese).
13.
Mukherjee, R., 1994, “Augmentation of Heat Transfer in Low Reynolds Number Flow Inside Tubes by the Use of Wire-Fin Inserts,” Proceedings of the 10th International Heat Transfer Conference, Institute of Chemical Engineering London, UK, pp. 173–176.
14.
Gibson
,
W. D.
,
1998
, “
Heat Exchangers: Warming up to Special Needs
,”
Chem. Eng.
,
105
, No.
13
, pp.
45
–
53
.
15.
Monheit, M., 1987, “Experimental Evaluation of the Convective Characteristics of Tubes with Twisted Tape Inserts,” Advances in Enhanced Heat Transfer, AMSE, New York, pp. 11–18.
16.
Al-Fahed
,
S.
, and
Chakroun
,
W.
,
1996
, “
Effect of Tube-Tape Clearance on Heat Transfer for Fully Developed Turbulent Flow in a Horizontal Isothermal Tube
,”
Int. J. Heat Fluid Flow
,
17
, No.
2
, pp.
173
–
178
.
17.
Al-Fahed
,
S.
,
Chamra
,
L. M.
, and
Chakroun
,
W.
,
1998
, “
Pressure Drop and Heat Transfer Comparison for Both Microfin Tube and Twisted-Tape Inserts in Laminar Flow
,”
Exp. Therm. Fluid Sci.
,
18
, No.
4
, pp.
323
–
333
.
18.
Bergles, A. E., Blumenkrantz, A. R., and Taborek, J., 1974, “Performance Evaluation Criteria for Enhanced Heat Transfer Surfaces,” Proceedings of the 5th International Heat Transfer Conference, Tokyo, Vol. 2, pp. 239–243.
19.
Patil, A. G., 1991, “Heat Transfer Augmentation in Laminar and Turbulent Flows in a Circular Tube Fitted with Varying Width Twisted Tapes,” M. tech. dissertation, IIT Powai, pp. 31–36.
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