Acoustic measurements of air entrainment by a plunging free water jet

1999 ◽  
Vol 105 (2) ◽  
pp. 1254-1255
Author(s):  
Thomas R. Hahn ◽  
Thomas K. Berger ◽  
Michael J. Buckingham
Keyword(s):  
Free Water ◽  
Air Entrainment ◽  
Water Jet ◽  
Acoustic Measurements

The Effect of Nozzle Type on Air Entrainment by Plunging Water Jets

2002 ◽  
Vol 37 (3) ◽  
pp. 599-612 ◽  
Author(s):  
Tamer Bagatur ◽  
Ahmet Baylar ◽  
Nusret Sekerdag
Keyword(s):  
Penetration Depth ◽  
Oxygen Transfer ◽  
Free Water ◽  
Air Entrainment ◽  
Water Jet ◽  
Transfer Efficiency ◽  
Entrainment Rate ◽  
Water Jets ◽  
Air Entrainment Rate ◽  
Oxygen Transfer Efficiency

Abstract In this study, for the plunging water jet aeration system using various inclined nozzle types, bubble penetration depth, air entrainment rate, water jet expansion, effect of water jet circumference at impact point, oxygen transfer coefficient and oxygen transfer efficiency which changed depending on the water jet velocity, were researched in an air-water system. Numerous studies were conducted with circular nozzles. The present study describes new experiments performed with different nozzle types. Three types of nozzles were examined, i.e., those with circular, ellipse and rectangle duct with rounded ends. Experimental results showed that water jets produced with ellipse and rectangle duct with rounded ends nozzles have very different flow characteristics, entrainment patterns on free water jet surface, and submerged water jet region within the receiving tank. Higher air entrainment rate and oxygen transfer efficiency was observed in the rectangle duct with rounded ends nozzle due to water jet expansion. Bubble penetration depth, however, is lower for the rectangle duct with rounded ends nozzle than for the other nozzles. The ellipse nozzle provided the highest bubble penetration depth. These results showed that it is appropriate to use ellipse nozzle in aeration of deep pool and rectangle duct with rounded ends nozzle in the applications where high bubble concentration is desirable.

scholarly journals Effect of wire mesh on the heat transfer from a flat plate under free water jet impingement quenching

2018 ◽  
Vol 57 (4) ◽  
pp. 3841-3850
Author(s):  
H.A. Abotaleb ◽  
M.Y. Abdelsalam ◽  
M.M. Aboelnasr
Keyword(s):  
Heat Transfer ◽  
Flat Plate ◽  
Free Water ◽  
Jet Impingement ◽  
Water Jet ◽  
Wire Mesh

scholarly journals The Effects of Downcomer Diameter on an Air Entrainment of Vertical Plunging Water Jet on The Water Surface

2021 ◽  
Vol 81 (2) ◽  
pp. 89-97
Author(s):  
Warjito ◽  
Ridho Irwansyah ◽  
Iqbal Yudianto ◽  
Leonardo Fabianto ◽  
Arya Amardani ◽  
...  
Keyword(s):  
High Speed ◽  
Qualitative Data ◽  
Bubble Formation ◽  
Air Entrainment ◽  
Water Jet ◽  
Water Desalination ◽  
Entrainment Rate ◽  
Clean Water ◽  
Depth Of Penetration ◽  
Plunging Water Jet

The difficulty in finding clean water is issued to become Indonesia’s problem in 2025. Seawater processing to produce clean water for commonly used or called water desalination will be a promising solution to solve the problem of clean water scarcity. One of the seawater desalination processes is to utilize micro-bubbles generated from air entrainment. Air entrainment is a phenomenon where the surrounding air is trapped in the water and forms a bubble. Using the vertical plunging jet setup will lead to bubble formation as a result of the collision between the vertical water jet and the pond surface below it. This study determines the effect of downcomer diameter on the parameters that influence the parameter of air entrainment quality by using a vertical plunging jet configuration. Some set up tools that support research consists of pumps, nozzle, downcomer, airflow meter, anemometer, and water pond. Results of the research are in the form of qualitative data such as videos and photos, by using a high-speed camera with backlighting. The qualitative data obtained will be processed with an image processing program to acquire quantitative data. The results of the study revealed that the downcomer diameter affects the air entrainment rate. On the other hand, jet velocity affects the area of dispersion and depth of penetration.

Air Entrainment by Plunging Water Jet

2004 ◽  
Vol 2004.41 (0) ◽  
pp. 59-60
Author(s):  
Yusuke MIZUTANI ◽  
Atsushi SASAKI ◽  
Masaharu MATSUBARA ◽  
Yoshiaki TSUCHIYA
Keyword(s):  
Air Entrainment ◽  
Water Jet ◽  
Plunging Water Jet

Statistical Characteristics in Water Jet Discharged From a Central-Body Nozzle

2010 ◽  
Author(s):  
Can Kang ◽  
Feng Zhang ◽  
Dong Liu ◽  
Minguan Yang
Keyword(s):  
Central Body ◽  
Droplet Diameter ◽  
Maximum Velocity ◽  
Free Water ◽  
Ambient Air ◽  
Water Jet ◽  
Pressure Increase ◽  
Statistical Characteristics ◽  
Diameter Distribution ◽  
Turbulent Fluctuation

As a special nozzle, central-body nozzle has attracted a lot of attention since its concept was proposed in 1980s. With Karman vortex street principle and phase-change theory, cavitation is expected to occur just after the central body. However, turbulent features in water jet flow discharged from central-body nozzle have not been illustrated by sufficient experimental data when water is ejected into ambient air. Under jet pressures of 11MPa, 13MPa and 17MPa, free water jet discharged from a central-body nozzle was experimentally studied. Phase Doppler particle anemometry (PDPA) was applied to measure non-intrusively the flow fields. Four traverse sections were selected for data visualization and representative description of the flow features. Control volumes at center and rim of the four sections were monitored for recording of every validated single droplet passing through. Experiment results indicate that pressure increase influences maximum velocity significantly. Obvious statistical characteristics exist at jet center and jet rim. The statistical feature of the droplet distribution varies slightly with pressure increase. Turbulent fluctuation is proved to be in reasonable relation to droplet behavior and droplet diameter distribution.

Experimental Research on a Pump Suction Sump With Improved Structure

2005 ◽  
Author(s):  
Yi Fan ◽  
Shuhong Liu ◽  
Yulin Wu ◽  
Yong Li ◽  
Zhaofeng Xu
Keyword(s):  
Water Depth ◽  
Water Surface ◽  
Free Water ◽  
Air Entrainment ◽  
Critical Flow ◽  
Height Measurement ◽  
Critical Flow Rate ◽  
Pumping System ◽  
Pump Station ◽  
Pump Sump

Pump suction sump is an important part of pump station and its flow situations influence the performance of pumping system greatly. In this paper, the pump suction sump with particular structure is designed to improve the flow situations near the pump intake. In order to validate the effect of the improved structure, three experiments were carried out on both the original and improved structures, including the experiment of critical flow rate for air entrainment, the experiment of free water surface height measurement, and 3D PIV experiments at the pump sump. The results of the experiments show that water depth and inlet flow velocity influence the flow situations greatly. The results also show that the improved structure is useful to improve flow situations in pump suction sump.

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