0
Research Papers: Flows in Complex Systems

Structure Analysis of a Low Reynolds Number Turbulent Submerged Jet Interacting With a Free Surface

[+] Author and Article Information
Qian Wen

Key Lab of Education Ministry for Power
Machinery and Engineering,
School of Mechanical Engineering,
Shanghai Jiao Tong University,
800 Dongchuan Road,
Shanghai 200240, China

Hyun Dong Kim

School of Mechanical Engineering,
Pusan National University,
Busan 609-735, South Korea

Ying Zheng Liu

Key Lab of Education Ministry for
Power Machinery and Engineering,
School of Mechanical Engineering,
Shanghai Jiao Tong University,
800 Dongchuan Road,
Shanghai 200240, China

Kyung Chun Kim

School of Mechanical Engineering,
Pusan National University,
Busan 609-735, South Korea
e-mail: kckim@pusan.ac.kr

1Corresponding author.

Contributed by the Fluids Engineering Division of ASME for publication in the JOURNAL OF FLUIDS ENGINEERING. Manuscript received June 15, 2013; final manuscript received May 4, 2014; published online July 24, 2014. Assoc. Editor: Peter Vorobieff.

J. Fluids Eng 136(10), 101104 (Jul 24, 2014) (16 pages) Paper No: FE-13-1378; doi: 10.1115/1.4027620 History: Received June 15, 2013; Revised May 04, 2014

In this study, the spatial structures of a submerged turbulent jet interacting with a free surface were investigated experimentally. The jet axis was located at three different depths (H/D = 2, H/D = 4 and H/D = 6) beneath the free surface and the Reynolds number was fixed as 3480. Laser-induced fluorescence technique was used for qualitative visualization and the time-resolved particle image velocimetry technique was used for the quantitative measurements. The dynamics of the flow structures were examined further using the proper orthogonal decomposition analysis technique. The results revealed that the dynamic characteristics of large-scale turbulent motions were significantly different with the submerged depths. In case of H/D = 2, the dominant spatial structures displayed a surface vibration induced reverse flow along the boundary, and its subsequent deflection changed the flow structures in the horizontal center plane. The violent free surface vibration caused an unsteady up-and-down motion of the flow structures and had a “squeeze effect” on the flow structures. In case of H/D = 4, the upwelling motion of some vortices in the jet and their subsequently downward entrainment motion significantly changed the dominant spatial structures both in the vertical and horizontal central planes. When the jet was fully attached to the free surface, the vortical structures underwent a merging and restructuring process due to the vertical confinement of the free surface. In case of H/D = 6, the dominant spatial structures both in the vertical and horizontal central planes showed an approximately symmetric pattern, indicating that the dominant structures were not changed by the free surface. After attached to the free surface, the jet did not undergo a merging and restructuring process as shown in case of H/D = 4.

Copyright © 2014 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 1

Schematic diagram of the experimental setup and measurement section. (a) Experimental setup and coordinate system and (b) measurement section of the time-resolved PIV.

Grahic Jump Location
Fig. 2

LIF images. (a) A region covered X/D = 13–29 for H/D = 2, (b) A region covered X/D = 21–37 for H/D = 4, and (c) a region covered X/D = 21–37 for H/D = 6.

Grahic Jump Location
Fig. 3

Normalized mean streamwise velocity contour and vector profiles, Uc is the centerline velocity at the respective X/D location. (a) H/D = 2, (b) H/D = 4, and (c) H/D = 6.

Grahic Jump Location
Fig. 4

Vertical profiles (on the vertical central plane) of the streamwise mean velocity at X/D = 28. The vertical dashed line indicates the position of the jet centerline.

Grahic Jump Location
Fig. 5

First four eigenmodes of H/D = 2 on the vertical central plane. (a) 1st mode, (b) 2nd mode, (c) 3rd mode, and (d) 4th mode.

Grahic Jump Location
Fig. 6

A dynamic plot of the instantaneous flow field reconstructed by the first four eigenmodes (H/D = 2 vertical central plane)

Grahic Jump Location
Fig. 7

First four eigenmodes of H/D = 2 on the horizontal central plane. (a) 1st mode, (b) 2nd mode, (c) 3rd mode, and (d) 4th mode.

Grahic Jump Location
Fig. 8

A dynamic plot of the instantaneous flow field reconstructed by the first four eigenmodes (H/D = 2 horizontal central plane)

Grahic Jump Location
Fig. 9

First four eigenmodes of H/D = 4 (Part I) on the vertical central plane. (a) 1st mode, (b) 2nd mode, (c) 3rd mode, and (d) 4th mode.

Grahic Jump Location
Fig. 10

First four eigenmodes of H/D = 4 (Part II) on the vertical central plane. (a) 1st mode, (b) 2nd mode, (c) 3rd mode, and (d) 4th mode.

Grahic Jump Location
Fig. 11

A dynamic plot of the instantaneous flow field reconstructed by the first four eigenmodes (H/D = 4 vertical central plane, Part I)

Grahic Jump Location
Fig. 12

A dynamic plot of the instantaneous flow field reconstructed by the first four eigenmodes (H/D = 4 vertical central plane, Part II)

Grahic Jump Location
Fig. 13

First four eigenmodes of H/D = 4 on the horizontal central plane. (a) 1st mode, (b) 2nd mode, (c) 3rd mode, and (d) 4th mode.

Grahic Jump Location
Fig. 14

A dynamic plot of the instantaneous flow field reconstructed by the first four eigenmodes (H/D = 4 horizontal central plane)

Grahic Jump Location
Fig. 15

First four eigenmodes of H/D = 6 (Part I) on the vertical central plane. (a) 1st mode, (b) 2nd mode, (c) 3rd mode, and (d) 4th mode.

Grahic Jump Location
Fig. 16

First four eigenmodes of H/D = 6 (Part II) on the vertical central plane. (a) 1st mode, (b) 2nd mode, (c) 3rd mode, and (d) 4th mode.

Grahic Jump Location
Fig. 17

A dynamic plot of the instantaneous flow field reconstructed by the first four eigenmodes (H/D = 6 vertical central plane, Part I)

Grahic Jump Location
Fig. 18

A dynamic plot of the instantaneous flow field reconstructed by the first four eigenmodes (H/D = 6 vertical central plane, Part II)

Grahic Jump Location
Fig. 19

First four eigenmodes of H/D = 6 on the horizontal central plane. (a) 1st mode, (b) 2nd mode, (c) 3rd mode, and (d) 4th mode.

Grahic Jump Location
Fig. 20

A dynamic plot of the instantaneous flow field reconstructed by the first four eigenmodes (H/D = 6 horizontal central plane)

Tables

Errata

Discussions

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