THERMAL SCIENCE

International Scientific Journal

EXPERIMENTAL AND NUMERICAL INVESTIGATION OF THERMAL PERFORMANCE OF CHANNELS WITH STAGGERED ARRAY-BASED DIMPLES

ABSTRACT
Numerical simulation coupled with experimental method was carried out to study the flow and heat transfer characteristics in rectangular channel with staggered array-based dimples. The effect of different dimple depths and Reynolds number were investigated using the shear stress transport turbulent model coupled with gamma-theta transition model. The results indicated that heat transfer and flow resistance of the dimpled surface increases with the increase of dimple depth. Moreover, the thermal performance is sensitive to the flow transition. Heat transfer in each single dimple region increases monotonously in the streamwise direction with Reynolds number increasing. Heat transfer characteristics almost remain the same when the flow is under fully laminar or turbulent but increases greatly when the flow is transited from laminar condition to turbulent condition. Besides, the variations of friction coefficients and thermal performance coefficients are quite similar to those of heat transfer enhancement coefficients, which firstly increases then decreases with the increase of Reynolds number. By comparing the experimental and numerical results, it is found that staggered array-based dimples with δ/D = 0.2 was the most effective structure from the aspect of thermal performance.
KEYWORDS
PAPER SUBMITTED: 2014-11-15
PAPER REVISED: 2015-02-02
PAPER ACCEPTED: 2015-03-05
PUBLISHED ONLINE: 2015-08-02
DOI REFERENCE: https://doi.org/10.2298/TSCI15S1S13X
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2015, VOLUME 19, ISSUE Supplement 1, PAGES [S213 - S219]
REFERENCES
  1. Terekhov, V. I., et al., Heat Transfer Coefficient and Aerodynamic Resistance on a Surface with a Single Dimple, Enhanced Heat Transfer, 4 (1997), 2, pp. 131-145
  2. Moon, H. K., et al., Channel Height Effect on Heat Transfer and Friction in a Dimpled Passage, Journal of Engineering for Gas Turbines and Power, 122 (2000), 2, pp. 307-313
  3. Chyu, M., et al., Heat Transfer Enhancement in Rectangular Channels with Concavities, Enhanced Heat Transfer, 6 (1999), 6, pp. 429-439
  4. Burgess, N. K., et al., Nusselt Number Behavior on Deep Dimpled Surfaces within a Channel, Journal of Heat Transfer, 125 (2003), 1, pp. 11-18
  5. Ligrani, P. M., et al., Nusselt Numbers and Flow Structure on and above a Shallow Dimpled Surface within a Channel Including Effects of Inlet Turbulence Intensity Level, Journal of Turbomachinery, 127 (2005), 2, pp. 321-330
  6. Burgess, N., Ligrani, P. M., Effects of Dimple Depth on Channel Nusselt Numbers and Friction Factors, Journal of Heat Transfer, 127 (2005), 8, pp. 839-847
  7. Won, S. Y., et al., Comparisons of Flow Structure above Dimpled Surfaces with Different Dimple Depths in a Channel, Physics of Fluids, 17 (2005), 4, pp. 1-9
  8. Won, S. Y., et al., Flow Characteristics along and above Dimpled Surfaces with Three Different Dimple Depths within a Channel, Journal of Mechanical Science and Technology, 21 (2007), 11, pp. 1901-1909
  9. Silva, C., E., et al., Flow Structure and Enhanced Heat Transfer in Channel Flow with Dimpled Surfaces: Application to Heat Sinks in Microelectronic Cooling. Journal of Electronic Packaging, 129 (2007), 2, pp. 157-166

© 2019 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence