scholarly journals Instrumentation to generate a two‐phase turbulent (bubble) submerged water jet for flow noise measurements

1994 ◽  
Vol 96 (5) ◽  
pp. 3333-3333
Author(s):  
Murray S. Korman
Keyword(s):  
Water Jet ◽  
Two Phase ◽  
Flow Noise ◽  
Noise Measurements

Acoustic emission-based flow noise detection and mechanism analysis for gas-liquid two-phase flow

Measurement ◽  
2021 ◽  
pp. 109480
Author(s):  
Ning Zhao ◽  
Chaofan Li ◽  
Huijun Jia ◽  
Fan Wang ◽  
Zhiyue Zhao ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Mechanism Analysis ◽  
Noise Detection ◽  
Two Phase ◽  
Flow Noise

Flow noise characterization of gas–liquid two-phase flow based on acoustic emission

Measurement ◽  
2013 ◽  
Vol 46 (10) ◽  
pp. 3887-3897 ◽  
Author(s):  
Lide Fang ◽  
Yujiao liang ◽  
Qinghua Lu ◽  
Xiaoting Li ◽  
Ran Liu ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Noise ◽  
Noise Characterization

Conceptual Design of the Flow Noise Simulator

2003 ◽  
Author(s):  
Ryuichi Sato ◽  
Takayuki Mori ◽  
Ryo Yakushiji ◽  
Kenji Naganuma ◽  
Masaharu Nishimura ◽  
...  
Keyword(s):  
Conceptual Design ◽  
Large Scale ◽  
Scale Model ◽  
Variable Pressure ◽  
Cavitation Noise ◽  
Flow Noise ◽  
Model Studies ◽  
Surface Ship ◽  
Noise Measurements ◽  
Under Construction

The Flow Noise Simulator (FNS) of the 1st Research Center of TRDI/JDA (Japan Defense Agency) is a large, variable pressure, recirculating water tunnel with very low background noise level. The tunnel is 20m high and 49m long, containing 2000m3 of water. The test section has a square cross section of 2m × 2m with 10m in length. It will accept large size surface ship models of 6m, submarine models of 4m in length and full scale ship appendix models. The FNS is currently under construction and will be accomplished in 2005. It will be used for a wide variety of hydrodynamic and hydroacoustic testing of surface ships and submarines, such as propeller cavitation noise measurements and propeller-hull interaction observation, with sufficiently large scale models. Conceptual design of the FNS was started in 1996 and evaluated by following scale model studies. This paper discusses some technical issues of the FNS.

Application of Two Phase Eulerian CFD Model to Simulate High Velocity Jet Induced Scour

2020 ◽  
Author(s):  
Nicholas S. Tavouktsoglou ◽  
Aggelos Dimakopoulos ◽  
Jeremy Spearman ◽  
Richard J. S. Whitehouse
Keyword(s):  
Numerical Model ◽  
High Velocity ◽  
Stokes Equations ◽  
Solid Phase ◽  
Three Dimensional ◽  
Water Jet ◽  
Ocean Engineering ◽  
Two Phase ◽  
Water Jets ◽  
Good Agreement

Abstract Submerged water jet causing soil excavation is a typical water-soil interaction process that occurs widely in many engineering disciplines. In hydraulic engineering for instance, a typical example would be scour downstream of headcuts, culverts, or dam spillways. In port and waterway engineering, erosion of the channel bed or quay wall by the propellers of passing ships are also typical water jet/soil interaction problems. In ocean engineering, trenching by impinging high-velocity water jets has been used as an efficient method for cable and pipeline burial. At present, physical modelling and simple prediction equations have been the main practical engineering tool for evaluating scour in these situations. However, with the increasing computational power of modern computers and the development of new Computational Fluid Dynamics (CFD) solvers, scour prediction in such engineering problems has become possible. In the present work three-dimensional (3D) numerical modelling has been applied to reproduce the capability of a pair of water jets to backfill an excavated trench. The simulations are carried out using a state-of-the-art three-dimensional Eulerian two-phase scour model based on the open source CFD software OpenFOAM. The fluid phase is resolved by solving modified Navier-Stokes equations, which take into consideration the influence of the solid phase, i.e., the soil particles. This paper first presents a validation of the numerical model against vertical jet erosion tests from the literature and conducted at HR Wallingford. The results of the model show good agreement with the experimental tests, with the numerical model predicting the scour hole depth and extent with good accuracy. The paper then presents a validation of the model’s ability to reproduce deposition which is evaluated through a comparison with settling velocity data and empirical formulations found in literature, again with the model showing good agreement. Finally, the model is applied to a prototype cable burial problem using a commercially available controlled flow jet excavator. The study found that the use of water jets can be effective (subject to confirmation of the time-scale required for real operations) for performing backfill operations but that the effectiveness is closely related to the type of sediment and selection of an appropriate jet discharge. As a result, in order for the water jet method to be effective for backfill, there is a requirement for a good description of the variation in sediment type along the trench and a requirement for the jet discharge to be varied as different sediment types are encountered.

scholarly journals A Vector Sensor-Based Acoustic Characterization System for Marine Renewable Energy

2020 ◽  
Vol 8 (3) ◽  
pp. 187
Author(s):  
Kaustubha Raghukumar ◽  
Grace Chang ◽  
Frank Spada ◽  
Craig Jones
Keyword(s):  
Renewable Energy ◽  
Three Dimensional ◽  
Acoustic Flow ◽  
Flow Noise ◽  
Vector Sensor ◽  
Acoustic Signature ◽  
Vector Sensors ◽  
Noise Measurements ◽  
Noise Data ◽  
Using Data

NoiseSpotter is a passive acoustic monitoring system that characterizes, classifies, and geo-locates anthropogenic and natural sounds in near real time. It was developed with the primary goal of supporting the evaluation of potential acoustic effects of offshore renewable energy projects. The system consists of a compact array of three acoustic vector sensors, which measures acoustic pressure and the three-dimensional particle velocity vector associated with the propagation of an acoustic wave, thereby inherently providing bearing information to an underwater source of sound. By utilizing an array of three vector sensors, the application of beamforming techniques can provide sound source localization, allowing for characterization of the acoustic signature of specific underwater acoustic sources. Here, performance characteristics of the system are presented, using data from controlled acoustic transmissions in a quiet environment and ambient noise measurements in an energetic tidal channel in the presence of non-acoustic flow noise. Data quality is demonstrated by the ability to reduce non-acoustic flow noise contamination, while system utility is shown by the ability to characterize and localize sources of sound in the underwater environment.

The Numerical Simulation of the Water Jet in Hydroentanglement

2011 ◽  
Vol 189-193 ◽  
pp. 2181-2184
Author(s):  
Heng Zhang ◽  
Xiao Ming Qian ◽  
Zhi Min Lu ◽  
Yuan Bai
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Multiphase Flow ◽  
Flow Model ◽  
Two Phase Flow ◽  
Water Jet ◽  
Phase Flow ◽  
Governing Equations ◽  
Two Phase ◽  
Set Up

The functions of hydroentangled nonwovens are determined by the degree of the fiber entanglement, which depend mainly on parameters of the water jet. According to the spun lacing technology, this paper set up the numerical model based on the simplified water jetting model, establishing the governing equations, and the blended two-phase flow as the multiphase flow model. This paper simulation the water needle after the water jetting from the water needle plate in the different pressure (100bar, 60bar, 45bar, 35bar).

Heat Transfer Performance of an Air-Assisted Impinging Water Jet Under a Fixed Pumping Power Constraint

2013 ◽  
Author(s):  
Daniel Trainer ◽  
Sung Jin Kim
Keyword(s):  
Heat Transfer ◽  
Flow Pattern ◽  
Heat Transfer Performance ◽  
Plug Flow ◽  
Water Jet ◽  
Air Injection ◽  
Transfer Performance ◽  
Pumping Power ◽  
Two Phase ◽  
Impingement Point

Air injection into a liquid impinging jet has been shown to be a method of improving non-phase change heat transfer rates by up to twice the normal amount. Previous work has shown that there exists an optimal operating point in terms of the volumetric fraction of air injection when the pumping power is held constant because of an optimal two-phase flow pattern. However, previous work focused on heat transfer from the impingement point only, and neglected performance at other points. The present work studies the local heat transfer performance of an air-assisted water jet, at the impingement point and at positions moving radially outward, under constant pumping power conditions. The area-averaged heat transfer is also considered. Heat transfer at the stagnation point is shown to be optimized between β = 0.1∼0.2, where a bubbly flow pattern exists. Nuavg(r/D ≤ 1) is optimized when the flow pattern was plug-flow and off-center peaks in Nur exist. Nuavg(r/D > 1) is optimized when the water is accelerated by the injected air, but splattering is avoided. Flow patterns have no direct effect outside the impingement region.

Analyses of Hydrodynamic Structure of Water Jet and Its Application to Jet Grouting

2003 ◽  
Author(s):  
Kenji Yoshida ◽  
Isao Kataoka ◽  
Hiroshi Yoshida ◽  
Mitsuru Yokoo ◽  
Kiyoshi Horii
Keyword(s):  
Constitutive Equations ◽  
Fluid Model ◽  
Momentum Conservation ◽  
Water Jet ◽  
Two Phase ◽  
Dispersed Flow ◽  
Two Fluid Model ◽  
Basic Equations ◽  
Physical Phenomena ◽  
Two Fluid

Analyses of water jet based on two-fluid model of two-phase dispersed flow have been carried out for single water jet and cross water jet in relation to the water jet technology in civil engineering. Mass and momentum conservation equations for liquid phase (droplet) gas phase (air) were formulated separately (two-fluid model formulation). Physical modeling of diffusion of droplets, drag coefficient of droplet in dispersed flow, shear stress at jet interface, etc has been carried out in detail and constitutive equations for these physical phenomena have been developed. Based on the two-fluid model basic equations and constitutive equations, one-dimensional analysis has been carried out considering simplified model. In the practical application of present analyses, some preliminary analyses on cross jet where two water jets collide with certain collision angles have been carried out and the predicted results reasonably explain the experimental results.

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