Enhancement of Heat Exchanger Performance by Using Dimpled Tube

  • Falah F. F. Al-Jabery Department of Mechanical Engineering/ University of Technology


The enhancement of heat exchanger performance was investigated using dimpled tubes tested at different Reynolds numbers, in the present work four types of dimpled tubes with a specified configuration manufactured, tested and then compared performance with the smooth tube and other passive techniques performance. Two dimpled arrangements along the tube were investigated, these are inline and staggered at constant pitch ratio X/d=4, the test results showed that Nusselts number (heat transfer) of the staggered array is higher than the inline array by 13%.  The effect of different depths of the dimple (14.5 mm and 18.5 mm) has been also investigated; a tube with large dimple diameter enhanced the Nusselts number by about 25% for the range of Reynolds number between 4000- 20000. The overall enhancement ratio was used to differentiate the passive technique and comparison of different configurations for the technique itself, the result depicted that the 10 mm dimple diameter with a pitch ratio of X/d= 4 gives better performance than the static mixer and twisted tape techniques. The overall enhancement ratio of the 10 mm dimple diameter is varied from (1.21 to 1.65) that means good performance for a range of Reynolds numbers (4000-20000). This indicates that 21- 65 % of heat transfer area can be saved at the same pumping power compared with the smooth tube heat exchanger. 


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P. Bharadwaj, A.D. Khondge,and A.W. Date, Heat transfer and pressure drop in a spirally grooved tube with twisted tape insert, proceeding of the International Journal of Heat and Mass transfer 52(2009) pp.1938-1944.

C. Nithiyesh Kumar, P. Murugesan,” Review on Twisted Tapes Heat Transfer Enhancement”, International Journal of Scientific & Engineering Research, Vol. 3, Issue 4, April-2012.

M. Udaya Kumar, M. Manzoor Hussian,and Md. Yousaf Ali,” Review of Heat Transfer Enhancement Techniques in Square Ducts with Inserts” ,International Journal of Emerging Technology and Advanced Engineering, Vol’ 3, Issue 8, August 2013.

Watcharin Noothong, Smith Eiamsa-ard, and Pongjet Promvonge,” Effect of Twisted-tape Inserts on Heat Transfer in a Tube”, The 2nd Joint International Conference on “Sustainable Energy and Environment (SEE 2006)”, 21-23 November 2006, Bangkok, Thailand.

P. Murugesan, K. Mayilsamy,and S. Sures,” Heat Transfer and Friction Factor in a Tube Equipped with U-cut Twisted Tape Insert”. JJMIE, Vol. 5, Number 6, PP. 559 – 565, Dec.2011.

Chinaruk Thianpong, Petpices Eiamsa-ard, Khwanchit Wongcharee, and Smith Eiamsa-ard,|” Compound heat transfer enhancement of a dimpled tube with a twisted tape swirl generator” International Communications in Heat and Mass Transfer 36, pp. 698–704,2009.

A. Khalil, A. E. Zohir and A. M. Farid,” Heat transfer characteristics and friction of turbulent swirling air flow through abrupt expansion”, American Journal of Scientific and Industrial Research, 1(2):pp. 364-374, 2010.

Promvonge, P., “Heat transfer behaviors in round tube with conical ring inserts”, Energy Conversation Management, 2007.

M .R. Jafari Nasr, G. T. Polley, and A. T. Zoghi, "Performance Evaluation of Heat Transfer Enhancement", CHISA, Praque, 2002.

BS1042 Standard,”Method of Measurement of Fluid in Closed Conduits”, Psrt 1,section 1.1,1981.

R. L. Webb, and N. Hyun Kim, “Principles of Enhanced Heat transfer”, Second Edition, Taylor Francis Group, 2005.

M. R. Jafari Nasr, A. T. Zoghi, and H. R. Khakadaman,”Performance Evaluation of Heat Transfer Enhancement in Heat Exchanger Design, Tahghigh, N 43, 2002.

J. P. Holman, "Heat Transfer ", Tenth Edition, Department of Mechanical Engineering Southern Methodist University (2010).

Ghinwa Sami Almamir, “Experimental and Numerical Investigation of Heat Transfer Enhancement for Dimple Tube” M.Sc. Thesis submitted to University of Technology Mechanical Engineering Department, 2014.

How to Cite
Al-Jabery, F. F. (2019). Enhancement of Heat Exchanger Performance by Using Dimpled Tube. Al-Khwarizmi Engineering Journal, 13(4), 41- 49. https://doi.org/10.22153/kej.2017.05.002