0
Research Papers: Multiphase Flows

Frequency in Shedding/Discharging Cavitation Clouds Determined by Visualization of a Submerged Cavitating Jet

[+] Author and Article Information
Ezddin A. F. Hutli, Milos S. Nedeljkovic

Faculty of Mechanical Engineering, University of Belgrade, Belgrade 11120, Serbia

J. Fluids Eng 130(2), 021304 (Jan 31, 2008) (8 pages) doi:10.1115/1.2813125 History: Received September 23, 2006; Revised July 11, 2007; Published January 31, 2008

Visualization of a highly submerged cavitating water jet was done by high-speed camera photography in order to study and understand the jet structure and the behavior of cloud cavitation within time and space. The influencing parameters, such as injection pressure, nozzle diameter and geometry, and nozzle direction (convergent and divergent), were experimentally proven to be very significant. Periodical shedding and discharging of cavitation clouds have been also analyzed and the corresponding frequency was determined by cloud shape analysis. Additionally, the dependence of this frequency on injection pressure and nozzle geometry has been analyzed and a simple formula of correspondence has been proposed. The formula has been tested on self-measured and literature data. The recordings of sonoluminescence phenomenon proved the bubble collapse everywhere along the jet.

FIGURES IN THIS ARTICLE
<>
Copyright © 2008 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 4

(Left-two columns) Conditions: P1=105bars, P2=2.06bars, VJ=124m∕s, σ=0.02568, T=18.5°C. (Right-two columns) Conditions: P1=177bars, P2=2.06bars, VJ=162m∕s, σ=0.0155, T=18.5°C. Convergent nozzle. X∕d=57.044, frame rate: 24,000fps, shutter frequency: 1∕250,000s, resolution 512×128, and number of frames in a film: 300 frames.

Grahic Jump Location
Figure 5

(Left-two columns) Conditions: P1=90.5bars, P2=1.89bars, VJ=18.2m∕s, σ=1.142, T=20°C. (Right-two columns) Conditions: P1=267bars, P2=1.89bars, VJ=31.5m∕s, σ=0.37, T=20°C. Divergent nozzle. X∕d=25.67, frame rate: 24,000fps, shutter frequency: 1∕250,000s, resolution: 512×128, and number of frames in a film: 300 frames.

Grahic Jump Location
Figure 6

The variation of cloud cavitation length (Lc) with upstream pressure and nozzle geometry. S is shedding, D is discharging. (Left) authors’ data: (Right) data from Refs. 1,6.

Grahic Jump Location
Figure 7

Cavitating water jet cloud width (Wc) behavior at different values of x∕d; (Left) convergent nozzle; (Right) divergent nozzle

Grahic Jump Location
Figure 8

The first three diagrams represent cavitating water jet cloud width (Wc) behavior at different values of x∕d for convergent nozzle at injection pressure P1=105bars. The fourth diagram represents the cloud length (Lc) change with the time (measured along the center of the jet). The pattern is a sine wave for all and with the same frequency.

Grahic Jump Location
Figure 9

An attempt to observe the luminescence phenomenon in a cavitating jet. The flow from left to right. Conditions: P1=213bars, VJ=191m∕s, T=22°C (σ=0.0125, σ=0.0142, and σ=0.0207 starting from left to right).

Grahic Jump Location
Figure 1

Nozzle geometry (mm). From left to right: nozzle geometry, nozzle holder, ways of nozzle installation.

Grahic Jump Location
Figure 2

(Left) Schematic diagram of a cavitating jet machine. (1) plunger pump, (2) filter, (3) regulation valve, (4) temperature sensor, (5) high-pressure transducer, (6) test chamber, (7) valve, (8) low-pressure transducer, (9) safety valve, (10) tank, (11) circulation pump, (12) heat exchanger, (13) energy destroyer in the bypass, and (14) pressure gauge. (Right) the test chamber.

Grahic Jump Location
Figure 3

(Left-up) Visualization system, (Left-down) cavitating jet striking the specimen, and (Right) group of jet images obtained under the following conditions: convergent nozzle (Dout=0.45mm). P1=105bars, P2=2.06bars, VJ=124m∕s, σ=0.02568, T=18.5°C, X∕d=57.044. Camera: FASTCAM-APX 120K, frame rate: 50,000fps, shutter frequency: 1∕250,000s, resolution: 256×64, number of pictures in a film: 300 frames.

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