Recirculation accompanied by shear cavitation is a key flow feature in annular jet pumps (AJPs). In this study, a high-speed camera was used to capture the recirculation region and various types of cavity clouds. By monitoring the trajectories of the small bubbles, the main recirculation regions under each flow rate ratio were obtained. As the flow rate ratio decreases, the recirculation region continued expanding with the separation point moving upstream, while the reattachment point remained nearly stationary regardless of the decreasing flow rate ratio. Hill's spherical vortex theory was adopted to evaluate the variations of the recirculation regions. Moreover, the minimum local static wall pressure in the recirculation region decreases as well, which can promote the inception and development of shear cavitation. There are numerous vortices simultaneously induced by the large velocity gradient in the shear layer, the core of which becomes a potential site for cavitation. Consequently, with the growth of the recirculation region, three types of cavity clouds, viz., the ribbonlike, annular, and merged cavity clouds, appear in turn. The movement characteristics of these cavity clouds, including their inception, distortion, and collapse, are illustrated based on the high-speed imaging results. The ribbonlike and annular cavity clouds are both induced by the small vortices in the shear layer because of the low local pressure in the vortex core. However, the merged cavity clouds are caused by a combination of several ribbonlike and annular cavity clouds, which provides a larger scale and a longer life span. Hence, the collapse of the merged cavity clouds can cause a large pressure pulsation near the reattachment point of the recirculation region. The corresponding frequency spectra were also demonstrated based on the fast Fourier transform (FFT) method.
Skip Nav Destination
Article navigation
June 2016
Research-Article
Shear Cavitation in an Annular Jet Pump Under Recirculation Conditions
Longzhou Xiao,
Longzhou Xiao
School of Power and Mechanical Engineering,
Wuhan University;
Wuhan University;
Key Lab of Jet Theory and
New Technology of Hubei Province,
Wuhan 430072, Hubei, China
New Technology of Hubei Province,
Wuhan 430072, Hubei, China
Search for other works by this author on:
Xinping Long,
Xinping Long
School of Power and Mechanical Engineering,
Wuhan University;
Wuhan University;
Key Lab of Jet Theory and
New Technology of Hubei Province,
Wuhan 430072, Hubei, China
e-mail: xplong@whu.edu.cn
New Technology of Hubei Province,
Wuhan 430072, Hubei, China
e-mail: xplong@whu.edu.cn
Search for other works by this author on:
Junqiang Zhang
Junqiang Zhang
School of Power and Mechanical Engineering,
Wuhan University;
Wuhan University;
Key Lab of Jet Theory and
New Technology of Hubei Province,
Wuhan 430072, Hubei, China
New Technology of Hubei Province,
Wuhan 430072, Hubei, China
Search for other works by this author on:
Longzhou Xiao
School of Power and Mechanical Engineering,
Wuhan University;
Wuhan University;
Key Lab of Jet Theory and
New Technology of Hubei Province,
Wuhan 430072, Hubei, China
New Technology of Hubei Province,
Wuhan 430072, Hubei, China
Xinping Long
School of Power and Mechanical Engineering,
Wuhan University;
Wuhan University;
Key Lab of Jet Theory and
New Technology of Hubei Province,
Wuhan 430072, Hubei, China
e-mail: xplong@whu.edu.cn
New Technology of Hubei Province,
Wuhan 430072, Hubei, China
e-mail: xplong@whu.edu.cn
Junqiang Zhang
School of Power and Mechanical Engineering,
Wuhan University;
Wuhan University;
Key Lab of Jet Theory and
New Technology of Hubei Province,
Wuhan 430072, Hubei, China
New Technology of Hubei Province,
Wuhan 430072, Hubei, China
1Corresponding author.
Contributed by the Fluids Engineering Division of ASME for publication in the JOURNAL OF FLUIDS ENGINEERING. Manuscript received October 28, 2014; final manuscript received December 22, 2015; published online March 15, 2016. Assoc. Editor: Satoshi Watanabe.
J. Fluids Eng. Jun 2016, 138(6): 061303 (14 pages)
Published Online: March 15, 2016
Article history
Received:
October 28, 2014
Revised:
December 22, 2015
Citation
Xiao, L., Long, X., and Zhang, J. (March 15, 2016). "Shear Cavitation in an Annular Jet Pump Under Recirculation Conditions." ASME. J. Fluids Eng. June 2016; 138(6): 061303. https://doi.org/10.1115/1.4032487
Download citation file:
Get Email Alerts
Switching Events of Wakes Shed From Two Short Flapping Side-by-Side Cylinders
J. Fluids Eng (May 2025)
Related Articles
Numerical Simulation of Vortex Cavitation in a Three-Dimensional Submerged Transitional Jet
J. Fluids Eng (July,2005)
Prediction of Small-Scale Cavitation in a High Speed Flow Over an Open Cavity Using Large-Eddy Simulation
J. Fluids Eng (November,2010)
Cavitation–Vortex–Turbulence Interaction and One-Dimensional Model Prediction of Pressure for Hydrofoil ALE15 by Large Eddy Simulation
J. Fluids Eng (February,2019)
Modeling of 2-D Leakage Jet Cavitation as a Basic Study of Tip Leakage Vortex Cavitation
J. Fluids Eng (March,2001)
Related Proceedings Papers
Related Chapters
Cavitating Structures at Inception in Turbulent Shear Flow
Proceedings of the 10th International Symposium on Cavitation (CAV2018)
Experimental Investigation of Ventilated Supercavitation Under Unsteady Conditions
Proceedings of the 10th International Symposium on Cavitation (CAV2018)
Pulsating Supercavities: Occurrence and Behavior
Proceedings of the 10th International Symposium on Cavitation (CAV2018)