Research Papers: Jets, Wakes, and Impingment Cooling

Passive Control and Enhancement of Low Reynolds Number Slot Jets Through the Use of Tabs and Chevrons

[+] Author and Article Information
Andrew Sexton

Stokes Laboratories,
Bernal Institute,
University of Limerick,
Limerick V94 T9PX, Ireland
e-mail: andrew.sexton@ul.ie

Jeff Punch

Stokes Laboratories,
Bernal Institute,
University of Limerick,
Limerick V94 T9PX, Ireland

Jason Stafford, Nicholas Jeffers

Thermal Management Research Group,
Nokia Bell Labs,
Dublin D15 Y6NT, Ireland

1Corresponding author.

Contributed by the Heat Transfer Division of ASME for publication in the JOURNAL OF HEAT TRANSFER. Manuscript received February 22, 2017; final manuscript received July 10, 2017; published online October 10, 2017. Assoc. Editor: Danesh K. Tafti.

J. Heat Transfer 140(3), 032201 (Oct 10, 2017) (12 pages) Paper No: HT-17-1099; doi: 10.1115/1.4037786 History: Received February 22, 2017; Revised July 10, 2017

Liquid microjets are emerging as candidate primary or secondary heat exchangers for the thermal management of next generation photonic integrated circuits (PICs). However, the thermal and hydrodynamic behavior of confined, low Reynolds number liquid slot jets is not yet comprehensively understood. This investigation experimentally examined jet outlet modifications—in the form of tabs and chevrons—as techniques for passive control and enhancement of single-phase convective heat transfer. The investigation was carried out for slot jets in the laminar flow regime, with a Reynolds number range, based on the slot jet hydraulic diameter, of 100–500. A slot jet with an aspect ratio of 4 and a fixed confinement height to hydraulic diameter ratio (H/Dh) of 1 was considered. The local surface heat transfer and velocity field characteristics were measured using infrared (IR) thermography and particle image velocimetry (PIV) techniques. It was found that increases in area-averaged Nusselt number of up to 29% compared to the baseline case could be achieved without incurring additional hydrodynamic losses. It was also determined that the location and magnitude of Nusselt number and velocity peaks within the slot jet stagnation region could be passively controlled and enhanced through the application of outlet tabs of varying geometries and locations.

Copyright © 2018 by ASME
Your Session has timed out. Please sign back in to continue.


Enright, R. , Lei, S. , Nolan, K. , Mathews, I. , Shen, A. , Levaufre, G. , Frizzell, R. , Duan, G.-H. , and Hernon, D. , 2014, “ A Vision for Thermally Integrated Photonics Systems,” Bell Labs Tech. J., 19, pp. 31–45. [CrossRef]
Jeffers, N. , Stafford, J. , Nolan, K. , Donnelly, B. , Enright, R. , Punch, J. , Waddell, A. , Ehrlich, L. , O'Connor, J. , Sexton, A. , Blythman, R. , and Hernon, D. , 2014, “ Microfluidic Cooling of Photonic Integrated Circuits (PICS),” Fourth European Conference on Microfluidics, Limerick, Ireland, Dec. 10–12, pp. 1–4.
Gutmark, E. , and Grinstein, F. , 1999, “ Flow Control With Noncircular Jets 1,” Annu. Rev. Fluid Mech., 31(1), pp. 239–272. [CrossRef]
Chen, Y. , Ma, C.-F. , Qin, M. , and Li, Y. , 2006, “ Forced Convective Heat Transfer With Impinging Slot Jets of Meso-Scale,” Int. J. Heat Mass Transfer, 49(1), pp. 406–410. [CrossRef]
Choo, K. S. , Youn, Y. J. , Kim, S. J. , and Lee, D. H. , 2009, “ Heat Transfer Characteristics of a Micro-Scale Impinging Slot Jet,” Int. J. Heat Mass Transfer, 52(13–14), pp. 3169–3175. [CrossRef]
Zukowski, M. , 2013, “ Heat Transfer Performance of a Confined Single Slot Jet of Air Impinging on a Flat Surface,” Int. J. Heat Mass Transfer, 57(2), pp. 484–490. [CrossRef]
Lin, Z. , Chou, Y. , and Hung, Y. , 1997, “ Heat Transfer Behaviors of a Confined Slot Jet Impingement,” Int. J. Heat Mass Transfer, 40(5), pp. 1095–1107. [CrossRef]
Li, Q. , Xuan, Y. , and Yu, F. , 2012, “ Experimental Investigation of Submerged Single Jet Impingement Using Cu–Water Nanofluid,” Appl. Therm. Eng., 36, pp. 426–433. [CrossRef]
Yousefi, T. , Shojaeizadeh, E. , Mirbagheri, H. , Farahbaksh, B. , and Saghir, M. , 2013, “ An Experimental Investigation on the Impingement of a Planar Jet of Al2O3–Water Nanofluid on a V-Shaped Plate,” Exp. Therm. Fluid Sci., 50, pp. 114–126. [CrossRef]
Lee, J. , and Lee, S.-J. , 2000, “ The Effect of Nozzle Aspect Ratio on Stagnation Region Heat Transfer Characteristics of Elliptic Impinging Jet,” Int. J. Heat Mass Transfer, 43(4), pp. 555–575. [CrossRef]
Whelan, B. P. , and Robinson, A. J. , 2009, “ Nozzle Geometry Effects in Liquid Jet Array Impingement,” Appl. Therm. Eng., 29(11), pp. 2211–2221. [CrossRef]
Brignoni, L. A. , and Garimella, S. V. , 2000, “ Effects of Nozzle-Inlet Chamfering on Pressure Drop and Heat Transfer in Confined Air Jet Impingement,” Int. J. Heat Mass Transfer, 43(7), pp. 1133–1139. [CrossRef]
Lee, D. H. , Bae, J. R. , Park, H. J. , Lee, J. S. , and Ligrani, P. , 2011, “ Confined, Milliscale Unsteady Laminar Impinging Slot Jets and Surface Nusselt Numbers,” Int. J. Heat Mass Transfer, 54(11), pp. 2408–2418. [CrossRef]
Lee, D. H. , Bae, J. R. , Ryu, M. , and Ligrani, P. , 2012, “ Confined, Milliscale Unsteady Laminar Impinging Slot Jets: Effects of Slot Width on Surface Stagnation Point Nusselt Numbers,” ASME J. Electron. Packag., 134(4), p. 041004. [CrossRef]
Reeder, M. , and Samimy, M. , 1996, “ The Evolution of a Jet With Vortex-Generating Tabs: Real-Time Visualization and Quantitative Measurements,” J. Fluid Mech., 311, pp. 73–118. [CrossRef]
Kataoka, K. , Suguro, M. , Degawa, H. , Maruo, K. , and Mihata, I. , 1987, “ The Effect of Surface Renewal Due to Largescale Eddies on Jet Impingement Heat Transfer,” Int. J. Heat Mass Transfer, 30(3), pp. 559–567. [CrossRef]
Iwana, T. , Suenaga, K. , Shirai, K. , Kameya, Y. , Motosuke, M. , and Honami, S. , 2015, “ Heat Transfer and Fluid Flow Characteristics of Impinging Jet Using Combined Device With Triangular Tabs and Synthetic Jets,” Exp. Therm. Fluid Sci., 68, pp. 322–329. [CrossRef]
Gao, N. , Sun, H. , and Ewing, D. , 2003, “ Heat Transfer to Impinging Round Jets With Triangular Tabs,” Int. J. Heat Mass Transfer, 46(14), pp. 2557–2569. [CrossRef]
Hayashi, T. , Taki, J. , Nakanishi, Y. , Motosuke, M. , and Honami, S. , 2009, “ Experimental Study on Control of an Impinging Jet Heat Transfer Using Triangular Tabs,” J. Fluid Sci. Technol., 4(2), pp. 292–303. [CrossRef]
Zaman, K. B. , 1993, “ Streamwise Vorticity Generation and Mixing Enhancement in Free Jets by ‘Delta-Tabs',” AIAA Paper No. 93-3253.
Samimy, M. , Reeder, M. , and Zaman, K. , 1991, “ Supersonic Jet Mixing Enhancement by Vortex Generators,” AIAA Paper No. 91-2261-CP.
Zaman, K. , 1999, “ Spreading Characteristics of Compressible Jets From Nozzles of Various Geometries,” J. Fluid Mech., 383, pp. 197–228. [CrossRef]
Rahai, H. , 2010, “ Near-Field Characteristics of Wall Jets With Tabs,” Ph.D. thesis, University of California, Irvine, CA.
Violato, D. , Ianiro, A. , Cardone, G. , and Scarano, F. , 2012, “ Three-Dimensional Vortex Dynamics and Convective Heat Transfer in Circular and Chevron Impinging Jets,” Int. J. Heat Fluid Flow, 37, pp. 22–36. [CrossRef]
Zaman, K. , Bridges, J. , and Huff, D. , 2011, “ Evolution From ‘Tabs' to ‘Chevron Technology’—A Review,” Int. J. Aeroacoustics, 10(5–6), pp. 685–710. [CrossRef]
Anderson, S. L. , and Longmire, E. K. , 1995, “ Particle Motion in the Stagnation Zone of an Impinging Air Jet,” J. Fluid Mech., 299, pp. 333–366. [CrossRef]
Martin, J. , and Meiburg, E. , 1994, “ The Accumulation and Dispersion of Heavy Particles in Forced Two-Dimensional Mixing Layers. i. The Fundamental and Subharmonic Cases,” Phys. Fluids, 6(3), pp. 1116–1132. [CrossRef]
Tropea, C. , Yarin, A. L. , and Foss, J. F. , 2007, Springer Handbook of Experimental Fluid Mechanics, Vol. 1, Springer Science and Business Media, New York. [CrossRef]
Holman, J. , 2009, Heat Transfer, McGraw-Hill Education, New York.
Lindgren, B. , and Johansson, A. V. , 2002, “ Design and Evaluation of a Low-Speed Wind-Tunnel With Expanding Corners,” Royal Institute of Technology, Stockholm, Sweden, Technical Report No. TRITA-MEK.
Stafford, J. , Walsh, E. , and Egan, V. , 2012, “ A Statistical Analysis for Time-Averaged Turbulent and Fluctuating Flow Fields Using Particle Image Velocimetry,” Flow Meas. Instrum., 26, pp. 1–9. [CrossRef]
Jeffers, N. M. R. , 2009, “ On the Heat Transfer and Fluid Mechanics of a Normally-Impinging, Submerged and Confined Liquid Jet,” Ph.D. thesis, University of Limerick, Limerick, Ireland.
Sun, H. , Ma, C. , and Nakayama, W. , 1993, “ Local Characteristics of Convective Heat Transfer From Simulated Microelectronic Chips to Impinging Submerged Round Water Jets,” ASME J. Electron. Packag., 115(1), pp. 71–77. [CrossRef]
Garimella, S. V. , and Rice, R. , 1995, “ Confined and Submerged Liquid Jet Impingement Heat Transfer,” ASME J. Heat Transfer, 117(4), pp. 871–877. [CrossRef]
Munson, B. , Young, D. , Okiishi, T. , and Huebsch, W. , 2009, Fundamentals of Fluid Mechanics, Wiley, Hoboken, NJ.
Keane, R. D. , and Adrian, R. J. , 1990, “ Optimization of Particle Image Velocimeters. i. Double Pulsed Systems,” Meas. Sci. Technol., 1(11), pp. 1202–1215. [CrossRef]
TSI, 2011, “ Insight 4g-Tutorial Guide,” TSI Inc., Shoreview, MN.
Forliti, D. , Strykowski, P. , and Debatin, K. , 2000, “ Bias and Precision Errors of Digital Particle Image Velocimetry,” Exp. Fluids, 28(5), pp. 436–447. [CrossRef]
Stafford, J. , Walsh, E. , and Egan, V. , 2009, “ Characterizing Convective Heat Transfer Using Infrared Thermography and the Heated-Thin-Foil Technique,” Meas. Sci. Technol., 20(10), p. 105401. [CrossRef]
Nogueira, E. , Pereira, J. , Baesso, M. , and Bento, A. , 2003, “ Study of Layered and Defective Amorphous Solids by Means of Thermal Wave Method,” J. Non-Cryst. Solids, 318(3), pp. 314–321. [CrossRef]
Geers, L. F. G. , 2004, “ Multiple Impinging Jet Arrays. An Experimental Study on Flow and Heat Transfer,” Ph.D. thesis, Delft University of Technology, Delft, The Netherlands.
Lee, J. , and Lee, S.-J. , 2000, “ The Effect of Nozzle Configuration on Stagnation Region Heat Transfer Enhancement of Axisymmetric Jet Impingement,” Int. J. Heat Mass Transfer, 43(18), pp. 3497–3509. [CrossRef]
Ashforth-Frost, S. , and Jambunathan, K. , 1996, “ Effect of Nozzle Geometry and Semi-Confinement on the Potential Core of a Turbulent Axisymmetric Free Jet,” Int. Commun. Heat Mass Transfer, 23(2), pp. 155–162. [CrossRef]
Behnia, M. , Parneix, S. , Shabany, Y. , and Durbin, P. , 1999, “ Numerical Study of Turbulent Heat Transfer in Confined and Unconfined Impinging Jets,” Int. J. Heat Fluid Flow, 20(1), pp. 1–9. [CrossRef]
Sezai, I. , and Mohamad, A. , 1999, “ Three-Dimensional Simulation of Laminar Rectangular Impinging Jets, Flow Structure, and Heat Transfer,” ASME J. Heat Transfer, 121(1), pp. 50–56. [CrossRef]
Jeffers, N. , Stafford, J. , Conway, C. , Punch, J. , and Walsh, E. , 2016, “ The Influence of the Stagnation Zone on the Fluid Dynamics at the Nozzle Exit of a Confined and Submerged Impinging Jet,” Exp. Fluids, 57(2), pp. 1–15. [CrossRef]
Fabbri, M. , Wetter, A. , Mayer, B. , Brunschwiler, T. , Michel, B. , Rothuizen, H. , Linderman, R. , and Kloter, U. , 2006, “ Microchip Cooling Module Based on FC72 Slot Jet Arrays Without Cross-Flow,” IEEE 22nd Annual IEEE Semiconductor Thermal Measurement and Management Symposium, Dallas, TX, Mar. 14–16, pp. 54–58.
Chen, N. , and Yu, H. , 2014, “ Mechanism of Axis Switching in Low Aspect-Ratio Rectangular Jets,” Comput. Math. Appl., 67(2), pp. 437–444. [CrossRef]


Grahic Jump Location
Fig. 1

Schematic of tab geometries and locations for (a) baseline case, (b) minor double tabs, (c) minor triangle, (d) major triangle, (e) major chevron, and (f) major contour

Grahic Jump Location
Fig. 2

Illustration of the characteristic regions in confined slot jet dynamics

Grahic Jump Location
Fig. 3

(a) Schematic of the PIV measurement facility. (1) Water reservoir, (2) Totton DC40/10 centrifugal pump, (3) bypass valve, (4) Cole-Parmer direct-reading flow tube, (5) flow conditioning plenum and (b) detailed view of the test section (6) Litron Nano PIV Nd:YAG laser, (7) 2 MP camera, and (8) PIV test specimen.

Grahic Jump Location
Fig. 4

(a) Schematic of the local heat transfer test facility. (1) Lauda water bath, (2) Cole-Parmer digital gear pump, (3) Bronkhurst mass-flow meter, (4) flow conditioning plenum, and (5) flir IR camera. (b) Detailed view of the heated thin-foil test section (6) nozzle orifice plate, (7) three-dimensional printed tab, (8) stainless steel foil, (9) IR transparent glass, (10) copper bus bars, and (11) electrical input and tightening screw.

Grahic Jump Location
Fig. 5

Validation of the heat transfer measurement facility against established correlations from literature

Grahic Jump Location
Fig. 6

(a) Schematic of the pressure drop measurement facility. (1) Lauda water bath, (2) Cole-Parmer digital gear pump, (3) Bronkhurst mass-flow meter, (4) flow conditioning plenum, and (b) detailed view of the test section (5) flow outlet to reservoir, (6) tightening screws, (7) test specimen holder, and (8) stainless steel test specimen.

Grahic Jump Location
Fig. 7

Exit velocity profiles of the impinging jets along the major axis, normalized against the mean jet exit velocity (UMean) at ReDh = 500, for the (a) baseline, (b) minor double tab, (c) minor triangle, (d) major triangle, (e) major chevron, and (f) major contour outlet modifications

Grahic Jump Location
Fig. 8

Plots of wall jet velocity profiles along the major axis for ReDh = 500, normalized against Uy,Max for each geometry, for the (a) baseline, (b) minor double tab, (c) minor triangle, (d) major triangle, (e) major chevron, and (f) major contour outlet modifications

Grahic Jump Location
Fig. 9

Local NuDh distributions for all geometries (a)–(f) as a function of ReDh. NuDh and ReDh length scales are based on the hydraulic diameter of the baseline case: (a) β = 0, (b) β = 0.1, (c) β = 0.125, (d) β = 0.15, (e) β = 0.2, and (f) β = 0.295.

Grahic Jump Location
Fig. 10

(a) NuAvg as a function of the investigated surface area for ReDh = 500 and (b) hAvg as a function of V˙ for all geometries tested over a surface area of 36Dh2 along the major and minor axes

Grahic Jump Location
Fig. 11

(a) Pressure drop (ΔP) as a function of volumetric flow rate (V˙) and (b) head loss coefficient (K) as a function of ReDh

Grahic Jump Location
Fig. 12

Area-averaged Nusselt number (NuAvg) as a function of pumping power (PPump) for all geometries tested, over an area of 3Dh × 3Dh from the stagnation point along the major and minor axes



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