scholarly journals The Eksperimentation Study of Wave Transmission Trough Type Of Hollow Cube Breakwater

2019 ◽  
Vol 19 (3) ◽  
pp. 131
Author(s):  
Daniel Daniel ◽  
Budiman Budiman
Keyword(s):  
Wave Height ◽  
Water Depth ◽  
Model Simulation ◽  
Pole Density ◽  
Dimensional Parameter ◽  
Marine Engineering ◽  
Hollow Cube ◽  
Physical Model Simulation ◽  
The Relationship ◽  
Break Water

Erosion that occurs in break water by wave sand currents is a serious problem along coastal and inland shore [1]. This study aimed to assess the effect of the model height (Hm) and the pole density on the model on the reduction of the wave height and on the relationship between the non-dimensional parameter. The research was experimental with 2D physical model simulation which was conducted in the laboratory of Marine Engineering Faculty, Hasanuddin University. Several of configurations of Hollow-type breakwater models were made with different densities and model heights. The model scale use was 1:10 for the three model variations ((M1KB, M2KB, and M3KB) with the variations of the periods and of the  wave height, at 0,25 m water depth. The research results indicated that the parameters which showed  significant effects were the model height and the model density. These  parameters showed the t

scholarly journals Pengaruh Screen Layer Breakwater Terhadap Tinggi Run UP Gelombang pada Revetmen

2018 ◽  
Vol 5 (1) ◽  
pp. 7
Author(s):  
Budiman Budiman
Keyword(s):  
Wave Height ◽  
Model Simulation ◽  
Wave Length ◽  
Dimensional Parameter ◽  
Number Of Layers ◽  
Waves And Currents ◽  
Run Up ◽  
Physical Model Simulation ◽  
The Relationship ◽  
Textile Fabric

Erosion that occurs in revetment by waves and currents is a serious problem along coastal and inland shore 1. The aims of the study are to obtain influential parameter, to reduce the height of run up in the revetmet and get a non dimensional parameter of the relationship between the wave height and the wave run up on the revetment. The research is an experimental research with 2D physical model simulation, conducted in the laboratory of with some configurations of screen layer breakwater configuration models made from textile fabric with density and number of layer of different models. The model scale was 1:10 with three variations for models ((M1SL, M2SL, and M3SL) with variations of wave length and wave height, on some level of depth: 20, 15, and 10 cm. The results of the research indicated that the parameters found in this study are wave period (T), wave height (H), water depth (d), screen density (), the number of layers (N) and the distanceof the screen (Xm). The run up tend to decrease as the screen density value has smaller number of layers (N) and the distanceof the screen (Xm). In general, the study indicated that the stake of the screen layer can reduce the height of the run up in the revetment structure . The slope tan300 was 33% and produces non regression equation that shows the relationship between the dimensionless parameterwith run up (Ru/H), obtained Ru/H =, where= (); a and b respectively 2.9935 and 0.1293.

Surf zone transformation of wave height to water depth ratios

1992 ◽  
Vol 17 (1-2) ◽  
pp. 49-70 ◽  
Author(s):  
R.C. Nelson ◽  
J. Gonsalves
Keyword(s):  
Wave Height ◽  
Water Depth ◽  
Surf Zone

scholarly journals Structure of pond vegetation of a vereda in the Brazilian Cerrado

Rodriguésia ◽  
2011 ◽  
Vol 62 (4) ◽  
pp. 721-729 ◽  
Author(s):  
Suzana Neves Moreira ◽  
Arnildo Pott ◽  
Vali Joana Pott ◽  
Geraldo Alves Damasceno-Junior
Keyword(s):  
Water Depth ◽  
Rainy Season ◽  
Life Form ◽  
Mato Grosso ◽  
Relative Cover ◽  
Dry Seasons ◽  
The Relationship ◽  
Measured Water ◽  
Mato Grosso Do Sul ◽  
New Occurrences

Abstract This is the first report on aquatic macrophytes in ponds of veredas (palm swamps) in the Cerrado (Brazilian savanna). We studied a pond in a vereda in Terenos, Mato Grosso do Sul state, central-western Brazil, during drought and flood periods to assess plant community structure and the relationship between species distribution and water depth. Sampling was carried out in five permanent transects, along which we placed sampling units of 1 m2 quadrats every 5 m. We estimated visually the relative cover of each species, bare ground, dead matter, and exposed water. We also measured water depth. We recorded 77 species of 49 genera and 31 families. The number of species varied between seasons, and in the rainy season the amphibious life form was predominant. The richest families were Poaceae (15 species), Cyperaceae (11), Asteraceae (4) and Lentibulariaceae (4). The richest genera were Rhynchospora (4), Utricularia (4), Eleocharis (4), Aeschynomene (3), Bacopa (3), Ludwigia (3) and Panicum (3). We found six new occurrences for the cerrado. Eleocharis acutangula had the highest relative cover (rainy and dry seasons), followed by Bacopa reflexa (rainy season), Paspalum lenticulare (rainy and dry seasons), Leersia hexandra (rainy and dry seasons), and Sagittaria rhombifolia (rainy season). Some species were distributed mainly at shallower depths, others occurred in deeper water, whereas some species varied greatly in terms of depth. Heliotropium filiforme and Ludwigia nervosa were found only in the dry season. In the rainy season, as expected, the exclusive species were mostly true aquatics.

scholarly journals The Biodiversity–Biomass Relationship of Aquatic Macrophytes Is Regulated by Water Depth: A Case Study of a Shallow Mesotrophic Lake in China

2021 ◽  
Vol 9 ◽  
Author(s):  
Fei Ma ◽  
Lei Yang ◽  
Tian Lv ◽  
Zhenjun Zuo ◽  
Haocun Zhao ◽  
...  
Keyword(s):  
Water Depth ◽  
Aquatic Macrophyte ◽  
Interspecific Interactions ◽  
Species Identity ◽  
Community Biomass ◽  
Macrophyte Communities ◽  
Macrophyte Community ◽  
Evenness Indices ◽  
Aquatic Macrophyte Community ◽  
The Relationship

The relationship between biodiversity and productivity (or biomass production) (BPR) has been a popular topic in macroecology and debated for decades. However, this relationship is poorly understood in macrophyte communities, and the mechanism of the BPR pattern of the aquatic macrophyte community is not clear. We investigated 78 aquatic macrophyte communities in a shallow mesotrophic freshwater lake in the middle and lower reaches of the Yangtze River in China. We analyzed the relationship between biodiversity (species richness, diversity, and evenness indices) and community biomass, and the effects of water environments and interspecific interactions on biodiversity–biomass patterns. Unimodal patterns between community biomass and diversity indices instead of evenness indices are shown, and these indicate the importance of both the number and abundance of species when studying biodiversity–biomass patterns under mesotrophic conditions. These patterns were moderated by species identity biologically and water depth environmentally. However, water depth determined the distribution and growth of species with different life-forms as well as species identities through environmental filtering. These results demonstrate that water depth regulates the biodiversity–biomass pattern of the aquatic macrophyte community as a result of its effect on species identity and species distribution. Our study may provide useful information for conservation and restoration of macrophyte vegetation in shallow lakes through matching water depth and species or life-form combinations properly to reach high ecosystem functions and services.

The Vibration Isolation Effect Research of the Floating Raft Isolation System Based on the Adjustable Flexibility of Foundation

2013 ◽  
Vol 819 ◽  
pp. 115-119 ◽  
Author(s):  
Hui Wang ◽  
Ze Yu Weng ◽  
Gan Xiang ◽  
Bo Lu ◽  
Hong Gang Ding ◽  
...  
Keyword(s):  
Vibration Isolation ◽  
Test System ◽  
Isolation Effect ◽  
Isolation System ◽  
Elastic Beams ◽  
Floating Raft ◽  
Marine Engineering ◽  
Flexible Foundation ◽  
The Relationship ◽  
Theoretical Results

The floating raft isolation system is widely used in the field of marine engineering for its vibration isolation effect. Along with the application of light thinning structure of the ship, the flexibility of foundation of floating raft isolation system makes the vibration isolation effect vary widely between the practical floating raft isolation system and its theoretical results. In order to research the vibration isolation effect of the floating raft isolation system on different flexibility of foundation, the floating raft isolation system with flexible foundation is designed in this paper, and the adjustable flexibility of foundation is achieved by using elastic beams. With simulation and analysis of test system in ADAMS, the results of the relationship between flexibility and vibration isolation effect are obtained.

scholarly journals Pr3+ doping at the A-site of La0.67Ba0.33MnO3 nanocrystalline material: assessment of the relationship between structural and physical properties and Bean–Rodbell model simulation of disorder effects

RSC Advances ◽  
2019 ◽  
Vol 9 (44) ◽  
pp. 25627-25637 ◽  
Author(s):  
Ma. Oumezzine ◽  
Herbet Bezerra Sales ◽  
Ahmed Selmi ◽  
E. K. Hlil
Keyword(s):  
Physical Properties ◽  
Carrier Concentration ◽  
Nanocrystalline Material ◽  
Model Simulation ◽  
Pechini Method ◽  
Sol Gel ◽  
Disorder Effects ◽  
Bulk Nanocrystalline ◽  
A Site ◽  
The Relationship

Bulk nanocrystalline samples of (La1−xPrx)0.67Ba0.33MnO3 (0.075 ≤ x ≤ 0.30) manganites with a fixed carrier concentration are prepared by the sol–gel based Pechini method.

scholarly journals Study of the Installation Process of the Subsea Tree Passed Through the Splash Zone

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1014
Author(s):  
Yufang Li ◽  
Honglin Zhao ◽  
Ning Xu ◽  
Xiaoyu Wang ◽  
Deguo Wang
Keyword(s):  
Wave Height ◽  
Oil And Gas ◽  
Splash Zone ◽  
Safety Standards ◽  
Engineering Software ◽  
Safe Production ◽  
Operational Safety ◽  
Offshore Oil And Gas ◽  
Marine Engineering ◽  
Offshore Oil

The subsea tree is one of the critical pieces of equipment in the subsea production system, and its installation is related to the safe production of offshore oil and gas. Due to the differences in the form of the structures, the speed of entering the water, the marine environment, and other factors, the process of the structure entering the water is exceedingly complicated. During the engineering installation, the most dangerous phase involves the structure passing through the splash zone. Based on the theory of the movement of the subsea tree passing through the splash zone, Lingshui 17-2 subsea tree installation was analyzed with the marine engineering software OrcaFlex, and a sensitivity analysis of the lowering of the subsea tree was performed. During the splash zone phase, the wave height had the highest impact on the subsea tree, affecting the horizontal offset and cable load, which may lead to the oil tree capsizing and cable breakage. Furthermore, the velocity only affected the horizontal offset, and the overall effect was not noticeable. The operational safety window for the subsea tree installation was established according to the operational safety standards. Therefore, the recommended lowering speed was 0.50 m/s, while the flow velocity should not exceed 1.50 m/s, and the wave height should not be higher than 4.5 m.

scholarly journals Buried Depth of a Submarine Pipeline Based on Anchor Penetration

2019 ◽  
Vol 7 (8) ◽  
pp. 257
Author(s):  
Xueyuan Zhu ◽  
Qinglong Hao ◽  
Jie Zhang
Keyword(s):  
Numerical Simulation ◽  
Penetration Depth ◽  
Water Depth ◽  
Calculation Method ◽  
Water Surface ◽  
Submarine Pipeline ◽  
Projected Area ◽  
Actual Measurement ◽  
Calculation Results ◽  
The Relationship

Anchor penetration is an important issue involved in the study of submarine pipeline damage accidents. To explore the penetration of a ship’s anchor under certain conditions, this study investigated the motion and force of an anchor and formulated a calculation method for the bottoming speed of an anchor. Meanwhile, the depth of anchor penetration was calculated under different conditions according to bottoming speed through programming. Finally, the reliability of the calculation method for the penetration depth was verified by comparing the actual measurement and the numerical simulation. On the basis of the findings, the calculation results were further analyzed, and conclusions were derived regarding the relationship between anchor mass, the horizontal projected area of the anchor, the anchor height on the water surface, and water depth. The conclusions provide suggestions for the application of anchor penetration in terms of seabed depth with certain reference values.

Statistical Analysis of a Set of Basin Waves

2011 ◽  
Author(s):  
Jule Scharnke ◽  
Janou Hennig
Keyword(s):  
Statistical Analysis ◽  
Wave Height ◽  
Water Depth ◽  
Water Waves ◽  
Rayleigh Distribution ◽  
Second Order ◽  
Distribution Functions ◽  
Wave Crest ◽  
Intermediate Water ◽  
Wave Measurements

In a recent paper the effect of variations in calibrated wave parameters on wave crest and height distributions was analyzed (OMAE2010-20304, [1]). Theoretical distribution functions were compared to wave measurements with a variation in water depth, wave seed (group spectrum) and location of measurement for the same initial power spectrum. The wave crest distribution of the shallow water waves exceeded both second-order and Rayleigh distribution. Whereas, in intermediate water depth the measured crests followed the second order distribution. The distributions of the measured waves showed that different wave seeds result in the same wave height and crest distributions. Measured wave heights were lower closer to the wave maker. In this paper the results of the continued statistical analysis of basin waves are presented with focus on wave steepness and their influence on wave height and wave crest distributions. Furthermore, the sampling variability of the presented cases is assessed.

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