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A COMPUTATIONAL STUDY OF HEAT TRANSFER UNDER TWIN TURBULENT SLOT JETS IMPINGING ON PLANAR SMOOTH AND ROUGH SURFACES

ABSTRACT
The flow and heat transfer characteristics of twin turbulent slot jets impinging on planar smooth and rough surfaces are examined using a computational fluid dynamics model. The interaction between jets lowers the heat transfer performance of each jet in the zone where the wall jets collide. A single jet performs better than the equivalent twin jet. The average heat transfer under twin jets which are injected alternately so that each one of the pair of jets behaves like a single jet, is found to be better than twin jets issuing simultaneously. It is proposed that alternating jet flows in the twin jet arrangement is a simple novel way to enhance thermal performance of jet pairs. Along with parametric studies of the key flow and geometric parameters, effects of large temperature differences between the jet air and the target surface being heated, and model roughness of the target surface are also evaluated. Interestingly, roughness can lower the heat transfer performance in the impingement zone as the fluid can get trapped in the valleys in the rough surface.
KEYWORDS
PAPER SUBMITTED: 2015-11-30
PAPER REVISED: 2015-12-02
PAPER ACCEPTED: 2016-01-11
PUBLISHED ONLINE: 2016-01-30
DOI REFERENCE: https://doi.org/10.2298/TSCI151130016X
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2016, VOLUME 20, ISSUE Supplement 1, PAGES [S47 - S57]
REFERENCES
  1. Zuckerman, N., Lior, N., Jet Impingement Heat Transfer: Physics, Correlations, and Numerical Modeling, Advances in Heat Transfer, 39 (2006) pp. 565-631.
  2. Mujumdar, A.S., Impingement Drying, in: Handbook of Industrial Drying (Ed. A.S. Mujumdar), CRC Press, New York, USA, 2014, pp. 371-380
  3. Specht, E., Impinging Jet Drying, in: Modern Drying Technology Volume 5: Process Intensification (Ed. E. Tsotsas and A.S. Mujumdar), Wiley-VCH, Weinheim, Germany, 2014, pp. 1-24
  4. Xiao, H.-W., Mujumdar A.S., Impingement Drying: Applications and Future Trends, in Drying Technologies for Foods: Fundamentals & Applications (Ed. P.K. Nema, et al.), New India Publishing Agency, New Delhi, India, 2015, pp. 279-299
  5. Behnia, M., et al., Accurate Modeling of Impinging Jet Heat Transfer, Annual Research Briefs, Center for Turbulence Research, Stanford University, Stanford, USA, 1997, pp. 149-164
  6. Gabour, L.A., Lienhard J.H., Wall Roughness Effects on Stagnation-point Heat Transfer Beneath an Impinging Liquid Jet, Journal of Heat Transfer, 116 (1994), 1, pp. 81-86
  7. Beitelmal, A.H., Saad, M.A., Effects of Surface Roughness on the Average Heat Transfer of an Impinging Air Jet, International Communications in Heat and Mass Transfer, 27 (2000), 1, pp. 1-12
  8. Sagot, B., Antonini, G., Buron, F., Enhancement of jet-to-wall heat transfer using axisymmetric grooved impinging plates, International Journal of Thermal Sciences, 49 (2010), 6, pp. 1026-1030
  9. Qiu, S., et al., Enhanced Heat Transfer Characteristics of Conjugated Air Jet Impingement on a Finned Heat Sink, Thermal Science, 2015, DOI: 10.2298/TSCI141229030Q
  10. Halouane, Y., Mataoui, A., Iachachene, F., Turbulent Heat Transfer for Impinging Jet Flowing Insider a Cylindrical Hot Cavity, Thermal Science, 19 (2015), 1, pp. 141-154
  11. Xu, P., et al., Heat Transfer and Entropy Generation in Air Jet Impingement on a Model Rough Surface, International Communications in Heat and Mass Transfer, (2015)
  12. Ekkad,S.V., Kontrovitz, D., Jet Impingement Heat Transfer on Dimpled Target Surfaces, International Journal of Heat and Fluid Flow, 23 (2000), 1, pp. 22-28
  13. Lou, Z.W., et al., Effects of Geometric Parameters on Confined Impinging Jet Heat Transfer, Applied Thermal Engineering, 25 (2005), 17-18, pp. 2687-2697
  14. Zhang, D., et al., Numerical Investigation of Heat Transfer Performance of Synthetic Jet Impingement onto Dimpled/Protrusioned Surface, Thermal Science, 19 (2015), S1, pp. S221-S229
  15. Welty, J., et al., Fundamentals of Momentum, Heat, and Mass Transfer (5th Edition), John Wiley & Sons, New York, USA, 2008, pp. 678-690
  16. Hofmann, H.M., et al., Calculations of Steady and Pulsating Impinging Jets-An Assessment of 13 Widely used Turbulence Models, Numerical Heat Transfer, Part B: Fundamentals, 51 (2007) 6, pp. 565-583
  17. Sharif, MAR, Mothe, K.K., Parametric Study of Turbulent Slot-jet Impingement Heat Transfer From Concave Cylindrical Surfaces, International Journal of Thermal Science, 49 (2009), 2, pp. 428-442
  18. Parham, K., et al., A Numerical Study of Turbulent Opposed Impinging Jets Issuing from Triangular Nozzles with Different Geometries, Heat and Mass Transfer, 47 (2011), 4, pp. 427-437.
  19. Mladin, E.C., Zumbrunnen, D.A., Local Convective Heat Transfer to Submerged Pulsating Jets, International Journal of Heat and Mass Transfer, 40 (1997), 14, pp. 3305-3321
  20. Taghinia J., et al., Numerical Investigation of Twin-jet Impingement with Hybrid-type Turbulence Modeling, Applied Thermal Engineering, 73 (2014), pp. 650-659
  21. Xu, P., et al., Turbulent Impinging Jet Heat Transfer Enhancement due to Intermittent Pulsation, International Journal of Thermal Science, 49 (2010), 7, pp. 1247-1252
  22. Xu, P., et al., A Study on the Heat and Mass Transfer Properties of Multiple Pulsating Impinging Jets, International Communications in Heat and Mass Transfer, 39 (2012), 3, pp. 378-382
  23. Gitan, A.A., et al., Development of Pulsating Twin Jets Mechanism for Mixing Flow Heat Transfer Analysis, The Scientific World Journal, 2014 (2014) pp. 767614
  24. Herwig, H., Middelberg, G., The Physics of Unsteady Jet Impingement and Its Heat Transfer Performance, Acta Mechanica, 201 (2008), 1, pp. 171-184
  25. Shariatmadar, H., et al., Experimental and Numerical Study on Heat Transfer Characteristics of Various Geometrical Arrangement of Impinging Jet Arrays, International Journal of Thermal Science, 102 (2016), pp. 26-38

© 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