0
Research Papers: Fundamental Issues and Canonical Flows

Experimental Investigation of Nozzle Spacing Effects on Characteristics of Round Twin Free Jets

[+] Author and Article Information
Andrew Laban

Department of Mechanical Engineering,
University of Manitoba,
Winnipeg, MB R3T 5V6, Canada
e-mail: labana@myumanitoba.ca

Seyed Sobhan Aleyasin

Department of Mechanical Engineering,
University of Manitoba,
Winnipeg, MB R3T 5V6, Canada
e-mail: aleyasss@myumanitoba.ca

Mark Francis Tachie

Department of Mechanical Engineering,
University of Manitoba,
Winnipeg, MB R3T 5V6, Canada
e-mail: mark.tachie@umanitoba.ca

Mike Koupriyanov

Price Industries Limited,
Winnipeg, MB R2K 3Z9, Canada
e-mail: mikek@priceindustries.com

Contributed by the Fluids Engineering Division of ASME for publication in the JOURNAL OF FLUIDS ENGINEERING. Manuscript received April 13, 2018; final manuscript received November 11, 2018; published online January 7, 2019. Assoc. Editor: Philipp Epple.

J. Fluids Eng 141(7), 071201 (Jan 07, 2019) (11 pages) Paper No: FE-18-1263; doi: 10.1115/1.4041989 History: Received April 13, 2018; Revised November 11, 2018

The objective of this paper is to investigate the effects of nozzle spacing on the mean velocity and higher-order turbulent statistics of free twin round jets produced from sharp contraction nozzles. The experiments were performed in an air chamber where four nozzle spacing ratios, S/d = 2.8, 4.1, 5.5, and 7.1, were investigated at a fixed Reynolds number of 10,000. A planar particle image velocimetry (PIV) system was used to conduct the velocity measurements. The results show that downstream of the potential core, a reduction in spacing ratio leads to an earlier and more intense interaction between the jets, indicated by enhanced half-velocity width spread rate in the inner shear layers and a significant rise of turbulent intensities and vorticity thickness along the symmetry plane. A reduction in spacing ratio, however, confines the ambient fluid entrainment along the inner shear layers leading to a reduced core jet velocity decay rate. The closer proximity of the jets also leads to the decrease of Reynolds stresses in the inner shear layers but not in the outer shear layers. The Reynolds stress ratios along the jet centerline reveal the highest anisotropy in the potential core region.

FIGURES IN THIS ARTICLE
<>
Copyright © 2019 by ASME
Your Session has timed out. Please sign back in to continue.

References

Lin, Y. E. , and Sheu, M. J. , 1990, “ Investigation of Two Plane Parallel Unventilated Jets,” Exp. Fluids, 10(1), pp. 17–22. [CrossRef]
Nasr, A. , and Lai, J. C. S. , 1997, “ Two Parallel Plane Jets: Mean Flow and Effects of Acoustic Excitation,” Exp. Fluids, 22(3), pp. 251–260. [CrossRef]
Anderson, E. A. , and Spall, R. E. , 2001, “ Experimental and Numerical Investigation of Two-Dimensional Parallel Jets,” ASME J. Fluids Eng., 123(2), pp. 401–406. [CrossRef]
Okamoto, T. , and Yagita, M. , 1985, “ Interaction of Twin Turbulent Circular Jet,” JSME, 28(238), pp. 617–622. [CrossRef]
Harima, T. , Fujita, S. , and Osaka, H. , 2001, “ Mixing and Diffusion Processes of Twin Circular Free Jets With Various Nozzle Spacing,” Experimental Heat Transfer, Fluid Mechanics, and Thermodynamics, Edizioni ETS, Pisa, Italy, pp. 1017–1022.
Harima, T. , Fujita, S. , and Osaka, H. , 2005, “ Turbulent Properties of Twin Circular Free Jets With Various Nozzle Spacing,” International Symposium on Engineering Turbulence Modelling and Measurements (ETMM6), Sardinia, Italy, May 23–25, pp. 501–510.
Meslem, A. , Nastase, I. , and Allard, F. , 2010, “ Passive Mixing Control for Innovative Air Diffusion Terminal Devices for Buildings,” Build. Environ., 45(12), pp. 2679–2688. [CrossRef]
Aleyasin, S. S. , and Tachie, M. F. , 2018, “ Comparative Evaluation of Single/Twin round and Elliptic Jets Using Particle Image Velocimetry,” ASME Paper No. FEDSM2018-83495.
Gutmark, E. J. , and Wygnanski , 1976, “ The Planar Turbulent Jet,” J. Fluid Mech., 73(3), pp. 465–495. [CrossRef]
Aleyasin, S. S. , Tachie, M. F. , and Koupriyanov, M. , 2017, “ PIV Measurements in the Near and Intermediate Field Regions of Jets Issuing From Eight Different Nozzle Geometries,” Flow, Turbul. Combust., 99(2), pp. 329–351. [CrossRef]
Aleyasin, S. S. , Fathi, N. , Tachie, M. F. , and Koupriyanov, M. , 2017, “ Comparison of Turbulent Jets Issuing From Various Sharp Contoured Nozzles,” ASME Paper No. FEDSM2017-69419.
Aleyasin, S. S. , Fathi, N. , Tachie, M. F. , Vorobieff, P. , and Koupriyanov, M. , 2018, “ On the Development of Incompressible Round and Equilateral Triangular Jets Due to Reynolds Number Variation,” ASME J. Fluids Eng., 140(11), p. 111202. [CrossRef]
Aleyasin, S. S. , and Tachie, M. F. , 2018, “ Statistical Properties and Structural Analysis of Three-Dimensional Twin Round Jets Due to Variation in Reynolds Number,” Int. J. Heat Fluid Flow, (epub).
Abernethy, R. B. , Benedict, R. P. , and Dowdell, R. B. , 1985, “ ASME Measurement Uncertainty,” ASME J. Fluids Eng., 107(2), pp. 161–164. [CrossRef]
Vouros, A. , and Panidis, T. , 2008, “ Influence of a Secondary, Parallel, Low Reynolds Number, Round Jet on a Turbulent Axisymmetric Jet,” Exp. Therm. Fluid Sci., 32(8), pp. 1455–1467. [CrossRef]
Ghahremanian, S. , and Moshfegh, B. , 2015, “ Investigation in the Near-Field of a Row of Interacting Jets,” ASME J. Fluids Eng., 137(12), pp. 1–18. [CrossRef]
Lan, K. , and Jorgenson, J. W. , 2001, “ A Hybrid of Exponential and Gaussian Functions as a Simple Model of Asymmetric Chromatographic Peaks,” J. Chromatogr. A, 915(1–2), pp. 1–13. [CrossRef] [PubMed]
Brown, G. L. , and Roshko, A. , 1974, “ On Density Effects and Large Structure in Turbulent Mixing Layers,” J. Fluid Mech., 64(4), pp. 775–816. [CrossRef]
Essel, E. E. , and Tachie, M. F. , 2015, “ Roughness Effects on Turbulent Flow Downstream of a Backward Facing Step,” Flow, Turbul. Combust, 94(1), pp. 125–153. [CrossRef]
Essel, E. E. , Nematollahi, A. , Thacher, E. W. , and Tachie, M. F. , 2015, “ Effects of Upstream Roughness and Reynolds Number on Separated and Reattached Turbulent Flow,” J. Turbul., 16(9), pp. 872–899. [CrossRef]
Akon, A. F. , 2017, “ Effects of Turbulence on the Separating-Reattaching Flow Above Surface-Mounted, Three-Dimensional Bluff Bodies,” Ph.D. thesis, The University of Western Ontario, London, ON, Canada. https://ir.lib.uwo.ca/etd/4445/
Quinn, W. R. , 2006, “ Upstream Nozzle Shaping Effects on Near Field Flow in Round Turbulent Free Jets,” Eur. J. Mech. B/Fluids, 25(3), pp. 279–301. [CrossRef]
Hashiehbaf, A. , and Romano, G. P. , 2013, “ Particle Image Velocimetry Investigation on Mixing Enhancement of Non-Circular Sharp Edge Nozzles,” Int. J. Heat Fluid Flow, 44, pp. 208–221. [CrossRef]
Xu, M.-Y. , Tong, X.-Q. , Yue, D.-T. , Zhang, J.-P. , Mi, J.-C. , Nathan, G. J. , and Kalt, P. A. M. , 2014, “ Effect of Noncircular Orifice Plates on the Near Flow Field of Turbulent Free Jets,” Chin. Phys. B, 23(12), pp. 1–9. [CrossRef]
Mi, J. , and Nathan, G. J. , 2009, “ Statistical Properties of Turbulent Free Jets Issuing From Nine Differently—Shaped Nozzles,” Flow, Turbul. Combust., 84(4), pp. 583–606. https://link.springer.com/article/10.1007/s10494-009-9240-0
Quinn, W. R. , 2007, “ Experimental Study of the Near Field and Transition Region of a Free Jet Issuing From a Sharp-Edged Elliptic Orifice Plate,” Eur. J. Mech. B/Fluids, 26(4), pp. 583–614. [CrossRef]
Mi, J. , Kalt, P. , Nathan, G. J. , and Wong, C. Y. , 2007, “ PIV Measurements of a Turbulent Jet Issuing From Round Sharp-Edged Plate,” Exp. Fluids, 42(4), pp. 625–637. [CrossRef]
Mi, J. , Kalt, P. , and Nathan, G. J. , 2009, “ On Turbulent Lets Issuing From Notched-Rectangular and Circular Orifice Plates,” Flow, Turbul. Combust., 84(4), pp. 565–582. [CrossRef]
Xu, G. , and Antonia, R. A. , 2002, “ Effect of Different Initial Conditions on a Turbulent Round Free Jet,” Exp. Fluids, 33(5), pp. 677–683. [CrossRef]
Deo, R. C. , Mi, J. , and Nathan, G. J. , 2005, “ Dependence of a Plane Turbulent Jet on Its Nozzle Contraction Profile,” International Conference on Jets, Wakes and Separated Flows, Toba-shi, Mie, Japan, Oct. 5–8, pp. 1–6.
Mi, J. , Nathan, G. J. , and Nobes, D. S. , 2001, “ Mixing Characteristics of Axisymmetric Free Jets From a Contoured Nozzle, an Orifice Plate and a Pipe,” ASME J. Fluids Eng., 123(4), pp. 878–883. [CrossRef]

Figures

Grahic Jump Location
Fig. 1

Schematic of twin jet configuration

Grahic Jump Location
Fig. 2

(a) Schematic of test facility and (b) test round nozzle with a modified contraction. All units in millimeter.

Grahic Jump Location
Fig. 3

Contours of normalized streamwise mean velocity, U/Umax, and spanwise vorticity, Ωz×d/Umax, for ((a), (c)) S/d = 2.8 and ((b), (d)) S/d = 7.1

Grahic Jump Location
Fig. 4

(a) Evolution of normalized streamwise mean velocity along the centerline and symmetry line, (b) merging point, (c) combining points, and (d) normalized streamwise mean velocity along the symmetry line

Grahic Jump Location
Fig. 5

(a) Jet centerline velocity decay, (b) outer shear layer half-velocity width, (c) inner shear layer half-velocity width, and (d) local vorticity thickness along the jet's inner shear layer

Grahic Jump Location
Fig. 6

One-dimensional profiles of normalized streamwise mean velocity at selected locations for S/d = 2.8, 4.1, and 7.1

Grahic Jump Location
Fig. 7

Contours of normalized Reynolds shear stress, uv¯/Umax2, streamwise normal stresses, u2¯/Umax2, and transverse normal stresses, v2¯/Umax2, for ((a), (c), (e)) S/d = 2.8 and ((b), (d), (f)) S/d = 7.1

Grahic Jump Location
Fig. 8

Development of (a) urms/Umax and (b) vrms/Umax along the symmetry plane and jet centerline; development of (c) urms/Ucl and (d) vrms/Ucl along the jet centerline; and scaling of (e) urms and (f) vrms along the symmetry plane

Grahic Jump Location
Fig. 9

Reynolds normal stresses ratio along jet centerline

Grahic Jump Location
Fig. 10

One-dimensional profiles of normalized (a) Reynolds shear stresses, (b) streamwise normal stresses, and (c) transverse normal stresses at selected locations for S/d = 2.8, 4.1, and7.1

Grahic Jump Location
Fig. 11

Contours of normalized turbulent kinetic energy, (k/Umax2), production, (Pk×d/Umax3), convection, (Ck×d/Umax3), and turbulent diffusion, (Dk×d/Umax3), for ((a), (c), (e), (g)) S/d = 2.8 and ((b), (d), (f), (h)) S/d = 7.1

Tables

Errata

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