scholarly journals Lateral Force Acting on a Ship's Model Moving Laterally in Shallow Water and Blockage Effect Due to Side Walls of Water Tank

1991 ◽  
Vol 85 (0) ◽  
pp. 135-141 ◽  
Author(s):  
Hiroyuki SADAKANE ◽  
Masanori KANAZAWA
Keyword(s):  
Shallow Water ◽  
Lateral Force ◽  
Water Tank ◽  
Side Walls ◽  
Blockage Effect

Shallow‐water tank experiments and model comparisons over range‐dependent elastic bottoms

2008 ◽  
Vol 123 (5) ◽  
pp. 3602-3602
Author(s):  
Jon M. Collis ◽  
Michael D. Collins ◽  
Harry J. Simpson ◽  
Raymond J. Soukup ◽  
William L. Siegmann
Keyword(s):  
Shallow Water ◽  
Water Tank ◽  
Model Comparisons

scholarly journals Comparative Analysis between Experimental and Numerical Model resultsof a Jetin a Shallow Water Tank

2020 ◽  
Vol 14 ◽  
Keyword(s):  
Comparative Analysis ◽  
Turbulent Flow ◽  
Large Scale ◽  
Water Tank ◽  
Heat And Mass Exchange ◽  
Small Depth ◽  
Exchange Processes ◽  
Side Walls ◽  
Turbulent Modeling ◽  
Good Agreement

In this work a comparative analysis of a turbulent jet experiment produced by the injection of dyed water into a shallow tank filled with water of the same density and the results of a numerical modelare presented. Dye was injected with the source fluid as a tracer. The concentration of the dye in the shallow turbulent flow was determined using a video imaging technique.The present laboratory experiments were conducted in a tank of small depth, and it is significantly wide to avoid the effect of the side walls. The space between the parallel walls of the tank can be varied during the experiments. The large-scale turbulent flow in the water sheet between the walls of the tank is confined to essentially two-dimensional motion. The shear on the bottom of the tank is a momentum sink to be considered.A comparison of the numerical resultswith the experimental data showed a very good agreement in terms of the position reached by the jet at different times after injection is initialized. These findings are useful for turbulent modeling of the shallow shear flow and for application to the large scale heat and mass exchange processes in lagoons, lakes, the ocean and the atmosphere

scholarly journals EXPERIMENTAL STUDY OF SOLITARY WAVE EVOLUTION OVER A 3D SHALLOW SHELF

2011 ◽  
Vol 1 (32) ◽  
pp. 1 ◽  
Author(s):  
Patrick J. Lynett ◽  
David Swigler ◽  
Sangyoung Son ◽  
Duncan Bryant ◽  
Scott Socolofsky
Keyword(s):  
Free Surface ◽  
Shallow Water ◽  
Three Dimensional ◽  
Maximum Velocity ◽  
Turbulent Energy ◽  
Shelf Break ◽  
Plan View ◽  
Fluid Velocities ◽  
Water Region ◽  
Side Walls

A laboratory experiment was performed to investigate the three-dimensional turbulence and kinematic properties that develop due to a breaking solitary propagating over an irregular shallow water bathymetry. The bathymetry consisted of a deep water region connected to a shallow shelf via a relatively steep slope. The offshore boundary of the shelf break varied in the longshore direction, such that the shelf had a triangular shape in plan view, with the widest part of the shelf along the basin centerline. Free surface elevations and fluid velocities were measured using wave gauges and three-dimensional acoustic-Doppler velocimeters (ADVs), respectively. From the free surface elevations the evolution and runup of the wave was revealed; while from the ADVs, the velocity and turbulent energy was determined and specific turbulent events and coherent structures were identified. It was found that significant shoaling was confined to areas with gentler sloping bathymetry near the basin side walls and the runup varied weakly in the alongshore direction. The runup was characterized by a refraction-generated jetting mechanism caused by the convergence of water mass near the basin centerline. The jetting mechanism caused the greatest cross-shore velocities to be located near the basin centerline. The greatest turbulent events were well correlated to borefronts, of which there were four, caused by the leading wave, beach reflections, and shelf-trapped oscillations. Along the shelf break, a large, shallow-water eddy developed which was found to have a peculiar three-dimensional flow field, where maximum velocity components were found at mid-depth.

Computational Prediction of Electric Fields in Shallow Water Testing Environment

2009 ◽  
Author(s):  
Stephanie A. Wimmer ◽  
Virginia G. DeGiorgi ◽  
Elizabeth A. Hogan
Keyword(s):  
Shallow Water ◽  
Electric Fields ◽  
Deep Water ◽  
Cathodic Protection ◽  
Water Environment ◽  
Computational Prediction ◽  
Water Tank ◽  
Testing Environment ◽  
Field Environment ◽  
Cathodic Protection System

There has been an increased need for understanding of how ship’s cathodic protection systems work in shallow water environment. This is a result of the evolving role of the US Navy. The existing cathodic protection system design process relies on experimental processes. This paper investigates a proposed modification to a deep water experimental facility to allow for measurements of electrical fields, a pertinent design measurement, in shallow water conditions. The modifications involve the insertion of a false bottom in the existing deep water tank. The work presented here are a series of computational studies that establish that the insertion of a false bottom would provide an electric field environment that is equivalent to shallow water for the depths considered.

Hydrodynamic Forces Measurement in Still Water Tank and Theoretical Validation of a Bio-Dorsal Fin Propulsive System

2011 ◽  
Vol 105-107 ◽  
pp. 1980-1984
Author(s):  
De Feng Du ◽  
Xiao Qin Jiang
Keyword(s):  
Large Amplitude ◽  
Wave Amplitude ◽  
Periodic Variation ◽  
Lateral Force ◽  
Experimental Result ◽  
Wave Number ◽  
High Fidelity ◽  
Water Tank ◽  
Dorsal Fin ◽  
Force Variation

The simulation level of prototypes mimicking torsional wave propulsion is low at present. A new prototype which uses a combination of crank and rocker mechanisms and pleated-skirt-pattern membrane is presented in this paper. The prototype’s dorsal fin is of high fidelity, the waveform looks pretty smooth and the wave amplitude can reach 85 degrees. In still pool, measurement of thrust and lateral force of dorsal fin were performed with a one-component balance. The experimental results show: 1. the thrust on the dorsal fin has periodic variation, and the frequency of thrust variation is twice the fin frequency. 2. The lateral force on the dorsal fin also has periodic variation, and the frequency of lateral force variation is the same as the fin frequency. 3. The periodic mean thrust on the dorsal fin is proportional to the square of fin frequency, and the influence of fin frequency on dorsal fin is stronger as wave number increases. 4. The computed results of large-amplitude EBT coincide qualitatively with experimental result, but our computed propulsive forces are quantitatively smaller. (This work was supported by the National Natural Science Foundation of China (10572151).)

scholarly journals A study on unpredictable shallow water channel behavior by various multipath patterns and experimental data analysis

2021 ◽  
Vol 9 (4B) ◽  
Author(s):  
Sumithra G ◽  
◽  
Meganathan D ◽  
Keyword(s):  
Shallow Water ◽  
Short Range ◽  
Water Channel ◽  
Signal Propagation ◽  
Propagation Model ◽  
Signal Frequency ◽  
Line Of Sight ◽  
Water Tank ◽  
Multipath Signal ◽  
Multipath Signal Propagation

In shallow water applications, multipath signal propagation is a major concern for robust communication. Multipath signal propagation is not explicitly seen in the channel, even though it is a main contributor for signal degradation. This fact motivated us to simulate multipath patterns to understand its influence in short-range communication. In this paper, a three-path signal propagation model is presented, where, besides the line of sight (LOS) signal, other two non-line of sight (NLOS) signals contact any point of channel boundary to reach the receiver. In simulation, the combination of eight possible multipath patterns is converged to estimate the received signal. A source fixed in water-tank periodically transmits low frequency acoustic signals 1 kHz and 1.5 kHz to the channel, and the receiver records them. The experiment was repeated for various input signal strengths. It has been observed that the simulation results coincide with the measured values. The good reception is noticed for signal frequency 1 kHz at 2.5m and 1.5 kHz at 1.2m. This study identifies the optimal signal strength for better signal reception in short range, which drives to the establishment of high-quality communication in shallow water.

scholarly journals Study of Gasdynamics with a Shallow Water Tank

1942 ◽  
Vol 1942 (71) ◽  
pp. 155-169
Author(s):  
Jiro Sugiura
Keyword(s):  
Shallow Water ◽  
Water Tank

Nonlinear sloshing and passage through resonance in a shallow water tank

2005 ◽  
Vol 56 (4) ◽  
pp. 645-680 ◽  
Author(s):  
E. A. Cox ◽  
J. P. Gleeson ◽  
M. P. Mortell
Keyword(s):  
Shallow Water ◽  
Water Tank ◽  
Nonlinear Sloshing
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