Research Papers: Heat Transfer Enhancement

Experimental and Numerical Study of Heat Transfer and Flow Friction in Channels With Dimples of Different Shapes

[+] Author and Article Information
Yu Rao

Gas Turbine Research Institute,
School of Mechanical Engineering,
Shanghai Jiao Tong University,
Dongchuan Road 800,
Shanghai 200240, China
e-mail: yurao@sjtu.edu.cn

Yan Feng, Bo Li

Gas Turbine Research Institute,
School of Mechanical Engineering,
Shanghai Jiao Tong University,
Dongchuan Road 800,
Shanghai 200240, China

Bernhard Weigand

Institute of Aerospace Thermodynamics (ITLR),
University of Stuttgart,
Pfaffenwaldring 31,
Stuttgart 70569, Germany

1Corresponding author.

Contributed by the Heat Transfer Division of ASME for publication in the JOURNAL OF HEAT TRANSFER. Manuscript received May 29, 2014; final manuscript received November 6, 2014; published online December 2, 2014. Assoc. Editor: Danesh / D. K. Tafti.

J. Heat Transfer 137(3), 031901 (Mar 01, 2015) (10 pages) Paper No: HT-14-1353; doi: 10.1115/1.4029036 History: Received May 29, 2014; Revised November 06, 2014; Online December 02, 2014

An experimental and numerical study was conducted to investigate the effects of dimple shapes on the heat transfer and flow friction of a turbulent flow over dimpled surfaces with different dimple shapes: spherical, teardrop, elliptical, and inclined elliptical. These dimples all have the same depth. The heat transfer, friction factor, and flow structure characteristics in the cooling channels with dimples of different shapes have been obtained and compared with each other for a Reynolds number range of 8500–60,000. The study showed that the dimple shape can have distinctive effects on the heat transfer and flow structure in the dimpled channels. The teardrop dimples show the highest heat transfer, which is about 18% higher than the conventional spherical dimples; and the elliptical dimples have the lowest heat transfer, which is about 10% lower than the spherical dimples; and however the inclined elliptical dimples have comparable heat transfer and pressure loss performance with the spherical dimples. The experiments still showed the realistic heat transfer enhancement capabilities of the dimpled channels relative to a smooth rectangular channel flow under the same flow and thermal boundary conditions, even after considering the thermal entrance effects in the channel flow and the enlarged heat transfer (wetted) area due to the dimpled surface. The three-dimensional numerical computations showed different vortex flow structures and detailed heat transfer characteristics of the dimples with different shapes, which revealed the influential mechanisms of differently shaped dimples on the convective heat transfer enhancement.

Copyright © 2015 by ASME
Your Session has timed out. Please sign back in to continue.


Han, J. C., Dutta, S., and Ekkad, S., 2001, Gas Turbine Heat Transfer and Cooling Technology, Taylor and Francis, New York.
Ligrani, P. M., Oliveira, M. M., and Blaskovich, T., 2003, “Comparison of Heat Transfer Augmentation Techniques,” AIAA J., 41(3), pp. 337–362. [CrossRef]
Schukin, A. V., Kozlov, A. P., and Agachev, R. S., 1995, “Study and Application of Hemispheric Cavities for Surface Heat Transfer Augmentation,” ASME Paper No. 95-GT-59.
Rao, Y., and Zang, S. S., 2014, “Flow and Heat Transfer Characteristics in Latticework Cooling Channels With Dimple Vortex Generators,” ASME J. Turbomach., 136(2), p. 021017. [CrossRef]
Afanasyev, V. N., Chudnovsky, Y. P., Leontiev, A. I., and Roganov, P. S., 1993, “Turbulent Flow Friction and Heat Transfer Characteristics for Spherical Cavities on a Flat Plate,” Exp. Therm. Fluid Sci., 7(1), pp. 1–8. [CrossRef]
Chyu, M. K., Yu, Y., and Ding, H., 1999, “Heat Transfer Enhancement in Rectangular Channels With Concavities,” J. Enhanced Heat Transfer, 6(6), pp. 429–439. [CrossRef]
Moon, H. K., O’Connell, T., and Gletzer, B., 2000, “Channel Height Effect on Heat Transfer and Friction in a Dimpled Passage,” ASME J. Eng. Gas Turbine Power, 122(2), pp. 307–313. [CrossRef]
Burgess, N. K., and Ligrani, P. M., 2005, “Effects of Dimple Depth on Channel Nusselt Numbers and Friction Factors,” ASME J. Heat Transfer, 127(8), pp. 839–847. [CrossRef]
Ligrani, P. M., Harrison, J. L., Mahmood, G. I., and Hill, M. L., 2001, “Flow Structure Due to Dimple Depression on a Channel Surface,” Phys. Fluids, 13(11), pp. 3442–3451. [CrossRef]
Mahmood, G. I., Hill, M. L., Nelson, D. L., Ligrani, P. M., Moon, H. K., and Glezer, B., 2001, “Local Heat Transfer and Flow Structure on and Above a Dimpled Surface in a Channel,” ASME J. Turbomach., 123(1), pp. 115–123. [CrossRef]
Bunker, R. S., and Donnellan, K. F., 2003, “Heat Transfer and Friction Factors for Flows Inside Circular Tubes With Concavity Surfaces,” ASME J. Turbomach., 125(4), pp. 665–672. [CrossRef]
Coy, E. B., and Danczyk, S. A., 2011, “Measurements of the Effectiveness of Concave Spherical Dimples for Enhancement Heat Transfer,” J. Propul. Power, 27(5), pp. 955–958. [CrossRef]
Nishida, S., Murata, A., Saito, H., and Iwamoto, K., 2009, “Measurement of Heat and Fluid Flow on Surface With Teardrop-Shaped Dimples,” Proceedings of Asian Congress on Gas Turbines, Tokyo, Japan, Aug. 24–26, Paper No. ACGT 2009-TS41.
Kim, H. M., Moon, M. A., and Kim, K. Y., 2011, “Shape Optimization of Inclined Elliptic Dimples in a Cooling Channel,” J. Thermophys. Heat Transfer, 25(3), pp. 472–476. [CrossRef]
Acharya, S., and Zhou, F., 2012, “Experimental and Computational Study of Heat/Mass Transfer and Flow Structure for Four Dimple Shapes in a Square Internal Passage,” ASME J. Turbomach., 134(6), p. 061028. [CrossRef]
Park, J., and Ligrani, P. M., 2005, “Numerical Predictions of Heat Transfer and Fluid Flow Characteristics for Seven Different Dimpled Surfaces in a Channel,” Numer. Heat Transfer A, 47(3), pp. 209–232 [CrossRef].
Xie, G., Liu, J., Ligrani, P. M., and Zhang, W., 2013, “Numerical Analysis of Flow Structure and Heat Transfer Characteristics in Square Channels With Different Internal-Protruded Dimple Geometrics,” Int. J. Heat Mass Transfer, 67, pp. 81–97. [CrossRef]
Elyyan, M. A., and Tafti, D. K., 2008, “Large Eddy Simulation Investigation of Flow and Heat Transfer in a Channel With Dimples and Protrusions,” ASME J. Turbomach., 130(4), p. 041016. [CrossRef]
Isaev, S. A., Kornev, N. V., Leontiev, A. I., and Hassel, E., 2010, “Influence of the Reynolds Number and the Spherical Dimple Depth on Turbulent Heat Transfer and Hydraulic Loss in a Narrow Channel,” Int. J. Heat Mass Transfer, 53(1–3), pp. 178–197. [CrossRef]
Turnow, J., Kornev, N., Zhdanov, V., and Hassel, E., 2012, “Flow Structures and Heat Transfer on Dimples in a Staggered Arrangement,” Int. J. Heat Fluid Flow, 35, pp. 168–175. [CrossRef]
Kline, S. J., and McClintock, F. A., 1953, “Describing Uncertainties in Single-Sample Experiments,” Mech. Eng., 75, pp. 3–8.
ANSYS Inc., 2013, Fluent 14.5 Help Document.
Celik, I. B., Ghia, U., Roache, P. J., Freitas, C. J., Coleman, H., and Raad, P. E., 2008, “Procedure for Estimation and Reporting of Uncertainty Due to Discretization in CFD Applications,” ASME J. Fluids Eng., 130(7), p. 078001. [CrossRef]
Spring, S., Lauffer, D., Weigand, B., and Hase, M., 2010, “Experimental and Numerical Investigation of Impingement Cooling in a Combustor Liner Heat Shield,” ASME J. Turbomach., 132(1), p. 011003. [CrossRef]
Bergman, T., Lavine, A., Incropera, F. K., and Dewitt, D. P., 2011, Fundamentals of Heat and Mass Transfer, 7th ed., Wiley, Hoboken, NJ.
Gee, D. L., and Webb, R. L., 1980, “Forced Convection Heat Transfer in Helically Rib-Roughened Tubes,” Int. J. Heat Mass Transfer, 23(8), pp. 1127–1136. [CrossRef]
Liou, T.-M., and Hwang, J.-J., 1993, “Effect of Ridge Shapes on Turbulent Heat Transfer and Friction in a Rectangular Channel,” Int. J. Heat Mass Transfer, 36(4), pp. 931–940. [CrossRef]


Grahic Jump Location
Fig. 1

Dimple array geometrical parameters

Grahic Jump Location
Fig. 2

Geometrical parameters of the dimples with different shapes

Grahic Jump Location
Fig. 6

Averaged Nusselt numbers of the dimpled channels

Grahic Jump Location
Fig. 7

Heat transfer enhancement of the dimpled channels

Grahic Jump Location
Fig. 5

The mesh for the spherical dimple channel computation

Grahic Jump Location
Fig. 4

Schematic of the boundary conditions for the dimpled channel computation

Grahic Jump Location
Fig. 3

Schematic of the experimental system for the dimpled channels

Grahic Jump Location
Fig. 14

Comparisons of overall thermal performance of the dimpled channels

Grahic Jump Location
Fig. 8

Realistic heat transfer enhancement of the dimpled channels

Grahic Jump Location
Fig. 9

Local Nusselt numbers on the dimpled surfaces with various dimple shapes at Re = 50,500

Grahic Jump Location
Fig. 10

Friction factors of the dimpled channels

Grahic Jump Location
Fig. 11

Friction factor ratios of the dimpled channels

Grahic Jump Location
Fig. 12

Three-dimensional streamlines in the dimpled channels with various dimple shapes at Re = 50,500. The legend for the Nusselt numbers is the same with Fig. 9.

Grahic Jump Location
Fig. 13

Streamlines and TKE distribution in a plane with a distance of 0.25 mm away from the endwall in the dimpled channels for Re = 50,500



Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In