scholarly journals Non-Intrusive Measurements of Wave-Induced Flow over Dikes by Means of a Combined Ultrasound Doppler Velocimetry and Videography

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3053
Author(s):  
Maria Gabriella Gaeta ◽  
Massimo Guerrero ◽  
Sara Mizar Formentin ◽  
Giuseppina Palma ◽  
Barbara Zanuttigh
Keyword(s):  
Clustering Algorithm ◽  
Light Exposure ◽  
Front Propagation ◽  
Seeding Density ◽  
Volume Distribution ◽  
Direct Measurements ◽  
Induced Flow ◽  
Wave Front Propagation ◽  
The University ◽  
Wave Induced

The performance of non-intrusive instruments, such as acoustic profilers and cameras, to describe the wave-induced flow processes over maritime dike crest was investigated in experiments carried out at the University of Bologna. Direct and derived measurements from the acoustic probes deployed along the structure crest were discussed in relation to the observed backscatter rates. Image processing was implemented by means of clustering algorithm, in order to detect the free surface during overtopping events and characterize wave front propagation over the dike crest. UVP data were processed to indirectly derive flow depths and overtopping rates and compare them with the direct measurements in order to assess the measurement reliability and discuss their limits. Individual overtopping volume distribution as obtained by UVP data were estimated and compared with well-consolidated formulations, showing a good agreement. Finally, suggestions for an appropriate use of non-intrusive instruments to characterize a shallow, transient and aerated flow were provided, such as the control of the artificial seeding density, the use of a bi-static UVP configuration and adjustments to light exposure.

scholarly journals Study on Wave and Wave-Induced Flow Behind a Sand Protection Submerged Dike

2002 ◽  
Vol 18 ◽  
pp. 449-453
Author(s):  
Dong-Soo HUR ◽  
Kenji USHIKI ◽  
Norimi MIZUTANI ◽  
Koichiro IWATA
Keyword(s):  
Induced Flow ◽  
Wave Induced

Ship Operational and Safety Aspects of Ballast Water Exchange at Sea

1994 ◽  
Vol 31 (04) ◽  
pp. 315-326
Author(s):  
John B. Woodward ◽  
Michael G. Parsons ◽  
Armin W. Troesch
Keyword(s):  
Bending Moment ◽  
Bending Moments ◽  
University Of Michigan ◽  
Bulk Carrier ◽  
Rough Water ◽  
Design Values ◽  
Wave Heights ◽  
Ballast Tanks ◽  
The University ◽  
Wave Induced

A dry bulk carrier, a tanker, and a containership—taken as typical of ships trading to U.S. ports—are analyzed for possible hazards caused by emptying and refilling ballast tanks at sea. Using hydrostatic data furnished by the shipowners, hull bending moments and stabilities are investigated to find the tank-emptying operations that produce the greatest changes in those parameters. As should be expected, bending moment changes do not exceed allowable stillwater values. Changes in GM are insignificant. The worst hydrostatic cases serve as a guide to conditions that should be analyzed in rough water. The University of Michigan SHIPMO program shows that in waves of 10-ft significant height wave-induced bending moments and shears are far below the design values published by the American Bureau of Shipping. On the other hand, in waves of 20-ft significant height, the maximum wave heights that occur occasionally can cause moments or shears that exceed design values. For the 20-ft case, both linear and nonlinear versions of SHIPMO are used.

Centrifugal Wave Front Propagation Speed for Localizing the Origin of Ventricular Arrhythmias

2018 ◽  
Vol 4 (3) ◽  
pp. 355-363 ◽  
Author(s):  
Masaharu Masuda ◽  
Mitsutoshi Asai ◽  
Osamu Iida ◽  
Shin Okamoto ◽  
Takayuki Ishihara ◽  
...  
Keyword(s):  
Wave Front ◽  
Ventricular Arrhythmias ◽  
Propagation Speed ◽  
Front Propagation ◽  
Wave Front Propagation

Self-lubricated transport of bitumen froth

1999 ◽  
Vol 386 ◽  
pp. 127-148 ◽  
Author(s):  
DANIEL D. JOSEPH ◽  
RUNYAN BAI ◽  
CLARA MATA ◽  
KEN SURY ◽  
CHRIS GRANT
Keyword(s):  
Pressure Gradient ◽  
Oil Sands ◽  
Pipe Wall ◽  
Extraction Process ◽  
Hot Water ◽  
Turbulent Pipe Flow ◽  
University Of Minnesota ◽  
Lubricating Layer ◽  
Direct Measurements ◽  
The University

Bitumen froth is produced from the oil sands of Athabasca using the Clark's Hot Water Extraction process. When transported in a pipeline, water present in the froth is released in regions of high shear, namely at the pipe wall. This results in a lubricating layer of water that allows bitumen froth pumping at greatly reduced pressures and hence the potential for savings in pumping energy consumption. Experiments establishing the features of the self-lubrication phenomenon were carried out in a 25 mm diameter pipeloop at the University of Minnesota, and in a 0.6 m diameter pilot pipeline at Syncrude, Canada. The pressure gradient of lubricated flows in 25 mm, 50 mm and 0.6 m diameter pipes closely follow the empirical law of Blasius for turbulent pipe flow; the pressure gradient is proportional to the ratio of the 7/4th power of the velocity to the 5/4th power of the pipe diameter, but the constant of proportionality is about 10 to 20 times larger than that for water alone. We used Reichardt's model for turbulent Couette flow with a friction velocity based on the shear stress acting on the pipe wall due to the imposed pressure gradient to predict the effective thickness of the lubricating layer of water. The agreement with direct measurements is satisfactory. Mechanisms for self-lubrication are also considered.

scholarly journals LES of Asymmetric Wave-induced Flow

2011 ◽  
Author(s):  
J. B. Chen ◽  
J. F. Zhou ◽  
Q. Zhang ◽  
Jiachun Li ◽  
Song Fu
Keyword(s):  
Induced Flow ◽  
Wave Induced ◽  
Asymmetric Wave
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