Experimental Investigation of Wave Runup on Offshore Intake Wells in a Random Wave Environment

2019 ◽  
Author(s):  
V. Prabu Kumar ◽  
R. Sundaravadivelu ◽  
K. Murali
Keyword(s):  
Free Surface ◽  
Surface Water ◽  
Wave Height ◽  
Large Volume ◽  
Sea Water ◽  
Random Wave ◽  
Outer Face ◽  
Intake System ◽  
Diffraction Wave ◽  
Run Up

Abstract The seawater intake system is one of the essential operational units in many industries located in the coastal regions. The selection of the type of intake system to a specific sector depends on the total volume required and the quality of the sea water. The offshore seawater intake wells are a suitable option to meet the large volume water requirement and desired water quality. Sometimes two or more intake wells are installed to supply the large volume of the sea water. Since the increase in spacing between the wells leads to an increase in capital cost, it is predominant important to find the optimum distance between the wells. The present study focuses on the external and internal hydrodynamics of two caisson type offshore intake wells situated in random wave environment. Two wells are fabricated in 1:20 model scale and installed in the shallow wave basin and exposed to the random waves. The outer to outer face distance between two wells changed by concerning the outer diameter (D) of the well such that 1D, 1.5D and 2D. The wave run-up, diffraction wave height and free surface water oscillations inside the wells are measured. The distance between the two intake wells has a significant role in wave run-up and free surface oscillation inside the well. Besides, the H/d have a substantial influence on the wave run-up on the seaward face compared to the side and shoreward face in all three cases. Also, the diffraction wave height is minimum when the wells are separated by 1.5D distance. Moreover, wave run-up and free surface water oscillation are optimum when the separation distance between the wells is 1.5D.

Effects of Wave Height and Sea Water Level on Wave Overtopping and Wave Run-Up

1965 ◽  
Vol 8 (1) ◽  
pp. 141-151 ◽  
Author(s):  
Yuichi Iwagaki ◽  
Akira Shima ◽  
Masao Inoue
Keyword(s):  
Water Level ◽  
Wave Height ◽  
Sea Water ◽  
Wave Overtopping ◽  
Run Up

Numerical Study for Water Waves Generated by Debris Flow

2013 ◽  
Vol 671-674 ◽  
pp. 388-392
Author(s):  
Rui Jin Zhang ◽  
Hong Yue Sun ◽  
Hong Zhan Zhang ◽  
Hosoyamada Tokuzo
Keyword(s):  
Free Surface ◽  
Surface Water ◽  
Debris Flow ◽  
Water Waves ◽  
Water Wave ◽  
Numerical Study ◽  
Human Life ◽  
Shallow Water Approximation ◽  
Surface Water Waves ◽  
Run Up

Earthquake or rainfall can arouse landslide, which will cause debris flow. Free surface water waves generated by plunging of debris flow cause devastating damage on human life. In this study, a numerical scheme for debris flow and free surface water wave was developed based on shallow water approximation, in which the interaction between these two flows was included newly. Generation of waves by plunging of debris flow is highly non-linear phenomena. Original CIP method and first order up-wind scheme mixed with second order central derivative scheme were adopted to simulate collision of two initially separated fluids (debris flow and still water). Six cases have been adopted to simulate the generation, propagation and run-up of water waves generated by debris flow. The time series of these two flows for these six calculating cases show the interaction of these two flows. Numerical results for interaction of debris flow and generated water wave are quite satisfactory and reasonable.

Wave Run-Up Simulations With a Moving Large Volume Semi-Submersible Platform

2011 ◽  
Author(s):  
Rafael de Andrade Watai ◽  
Fabio Tadao Matsumoto ◽  
Joa˜o Vicente Sparano ◽  
Alexandre Nicolaos Simos ◽  
Marcos Donato A. S. Ferreira
Keyword(s):  
Free Surface ◽  
Large Volume ◽  
Stokes Equations ◽  
Scale Model ◽  
Uniform Grid ◽  
Small Scale ◽  
Regular Waves ◽  
Wave Basin ◽  
Free Surface Displacement ◽  
Run Up

Since July 2008, the Numerical Offshore Tank (TPN) of the University of Sa˜o Paulo and Petrobras have been working on a research project intended to improve knowledge and modeling of advanced hydrodynamics topics, such as the wave run-up phenomenon. Among other activities, wave basin tests were performed with small-scale model of a large volume semi-submersible designed to operate in Campos Basin. These tests evidenced significant run-up effects on its squared-section columns for the steepest waves in several design conditions. In order to evaluate the difficulties involved in modeling the wave run-up phenomenon, simplified tests were also carried out with the model fixed and moored in regular waves with varying steepness. Previous studies using a 2nd order BEM model and a VOF CFD code to predict free-surface elevations below the deck under regular waves were presented in Matsumoto et al. (2010). The studies illustrated considerable differences between the wave elevation results in fixed and moored model setup; however, by that time, the analysis of the moored model by a VOF CFD code was not yet complete. This paper, therefore, presents wave run-up estimations with a moving large volume semi-submersible platform performed with the CFD code ComFLOW, which solves the Navier-Stokes equations employing a local height function to the free surface displacement. The phenomenon is investigated by simulating the flow around the semi-submersible model under the influence of high steepness regular waves on a non-uniform grid. Platform motions, derived from a first order BEM code, are imposed and synchronized with the incoming wave. Aiming at avoiding numerical wave reflections, a damping zone is also applied and positioned downstream the platform model. Predicted results are compared to experimental data, measured by seven vertical wave probes located in different positions below the model deck. Although considerably time-consuming, it will be shown that simulations present very good agreement with the experimental results.

scholarly journals Carbon-14 in the Southern Indian Ocean

Radiocarbon ◽  
1980 ◽  
Vol 22 (3) ◽  
pp. 684-692 ◽  
Author(s):  
Georgette Delibrias
Keyword(s):  
Surface Water ◽  
Indian Ocean ◽  
Water Samples ◽  
Sea Water ◽  
Time Lag ◽  
Vertical Profiles ◽  
Carbon 14 ◽  
Middle Latitudes ◽  
The North ◽  
The Indian Ocean

14C measurements were carried out on sea water samples collected in 1973, in the Indian ocean. The results obtained for 9 vertical profiles between 27° S and 48°S are presented. In surface water, the bomb 14C content is maximum at middle latitudes. A time lag relative to the north hemisphere bomb 14C delivery is apparent. In the more southern latitudes, 14C content remains very low.

scholarly journals Interaction between Groundwater and Surface Water / Sea Water

2001 ◽  
Vol 43 (1) ◽  
pp. 41-42
Author(s):  
Makoto TANIGUCHI ◽  
Hiroyuki TOSAKA
Keyword(s):  
Surface Water ◽  
Sea Water

Stable isotopes in planktonic and benthic foraminifera from Arctic Ocean surface sediments

1988 ◽  
Vol 25 (5) ◽  
pp. 701-709 ◽  
Author(s):  
A. E. Aksu ◽  
G. Vilks
Keyword(s):  
Surface Water ◽  
Arctic Ocean ◽  
Sea Water ◽  
Ocean Surface ◽  
The Arctic ◽  
Size Fractions ◽  
Isotopic Compositions ◽  
Isotopic Analyses ◽  
Stable Isotopic ◽  
Surface Water Salinity

Oxygen and carbon isotopic analyses have been performed on the tests of Planulina wuellerstorfi and three size fractions of sinistral Neogloboquadrina pachyderma recovered from 33 Arctic Ocean surface-sediment samples. Stable isotopic compositions of N. pachyderma are found to be dependent on the test size: larger specimens show considerable enrichment in both δ18O and δ18C. The difference between the isotopic compositions of the 63–125 and 125–250 μm size fractions in N. pachyderma can be explained by biogenic fractionation effects during foraminiferal test growth. Larger (250–500 μm) N. pachyderma displayed accretions of secondary calcite, i.e., the outermost shell contained significant amounts of inorganically precipitated magnesium calcite. Thus, larger foraminifera may not be suited for down-core stable isotopic studies. There is a difference of ~2‰ between δ18O values of surface samples from the eastern and western Arctic Ocean, reflecting large differences between surface-water salinity in these regions. Therefore, oxygen isotopic data may have limited use as a chronostratigraphic tool in down-core studies in the Arctic Ocean, but we can use them to infer past variations in surface-water salinities. Planulina wuellerstorfi also showed depletions of both δ18O and δ18C in its calcite tests relative to calcite precipitated in isotopic equilibrium with ambient sea water; these depletions ranged from −0.8 to −0.9‰ in δ18Oand −1.2 to −0.9‰ in δ18C. This taxon is found to deposit its shell very close to the δ18C of ΣCO2 of bottom waters.

MEASUREMENTS OF PRIMARY PRODUCTION IN COASTAL SEA WATER USING A LARGE-VOLUME PLASTIC SPHERE

1961 ◽  
Vol 6 (3) ◽  
pp. 237-258 ◽  
Author(s):  
C. D. McAllister ◽  
T. R. Parsons ◽  
K. Stephens ◽  
J. D. H. Strickland
Keyword(s):  
Primary Production ◽  
Large Volume ◽  
Sea Water ◽  
Coastal Sea ◽  
Plastic Sphere

Blood Volumes, Blood Distribution and Sea-Water Spaces in Relation to Expansion and Retraction of the Foot in Bullia (Gastropoda)

1964 ◽  
Vol 41 (4) ◽  
pp. 837-854
Author(s):  
A. C. BROWN
Keyword(s):  
Large Volume ◽  
Sandy Beach ◽  
Sea Water ◽  
Blood Flows ◽  
Blood Distribution ◽  
Blood Volumes

1. The expansion and retraction of the foot has been studied in the prosobranchiate sandy-beach gastropod, Bullia. 2. In Bullia the foot is capable of an unusually great expansion, but this is not dependent upon an unusually large volume of blood. 3. Radiographical investigations have shown that on retraction blood flows direct from the pedal sinus to the visceral sinus system without passing through the heart, kidney or gill. 4. Investigation of the jets of water produced on retraction has shown that in the expanded animal the visceral region within the shell is surrounded by sea water. 5. The roles of blood movement and of contraction of the columella muscle, and also various other aspects of the circulation, are discussed.

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