scholarly journals PHYSICAL MODEL INVESTIGATION OF PARCEL SCALE MANGROVE EFFECTS ON FLOW HYDRODYNAMICS AND PRESSURES AND LOADS IN THE BUILT ENVIRONMENT

2020 ◽  
pp. 1
Author(s):  
Tori Tomiczek ◽  
Anna Wargula ◽  
Pedro Lomonaco ◽  
Sabella Goodwin ◽  
Dan Cox ◽  
...  
Keyword(s):  
Scale Effects ◽  
Coastal Communities ◽  
Physical Models ◽  
Flood Hazards ◽  
Structural Elements ◽  
Mangrove Species ◽  
Red Mangrove ◽  
Wave Basin ◽  
Directional Wave ◽  
Reduced Pressures

Rising seas, tropical cyclones, and tsunamis threaten increasingly populated coastal areas, leaving coastal communities searching for sustainable, resilient adaptation solutions to mitigate the impacts of chronic and acute coastal flood hazards. This work specifically investigates parcel-scale effects of the Rhizophora mangle (red mangrove) species during extreme wave and/or storm surge conditions. We constructed 100 physical models of the Rhizophora species' trunk-prop root system on a 1:16 scale, and conducted tests in Oregon State University's Directional Wave Basin to measure the effects of mangroves of varying cross-shore thickness on water surface elevation, water velocities, and load reduction on idealized inland structural elements. The presence of mangroves affected hydrodynamic conditions near the mangroves and reduced pressures and forces on inland structures.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/XjtCmHYvgVQ

Simulation of Hurricane Seas in a Multidirectional Wave Basin

1991 ◽  
Vol 113 (3) ◽  
pp. 219-227 ◽  
Author(s):  
A. Cornett ◽  
M. D. Miles
Keyword(s):  
Ocean Waves ◽  
Entropy Method ◽  
Wave Spectra ◽  
Single Wave ◽  
Wave Condition ◽  
Wave Basin ◽  
Wide Range ◽  
Directional Wave ◽  
Wave Conditions ◽  
Multidirectional Wave

This paper describes the generation and verification of four realistic sea states in a multidirectional wave basin, each representing a different storm wave condition in the Gulf of Mexico. In all cases, the degree of wave spreading and the mean direction of wave propagation are strongly dependent on frequency. Two of these sea states represent generic design wave conditions typical of hurricanes and winter storms and are defined by JONSWAP wave spectra and parametric spreading functions. Two additional sea states, representing the specific wave activity during hurricanes Betsy and Carmen, are defined by tabulated hindcast estimates of the directional wave energy spectrum. The Maximum Entropy Method (MEM) of directional wave analysis paired with a single-wave probe/ bi-directional current meter sensor is found to be the most satisfactory method to measure multidirectional seas in a wave basin over a wide range of wave conditions. The accuracy of the wave generation and analysis process is verified using residual directional spectra and numerically synthesized signals to supplement those measured in the basin. Reasons for discrepancy between the measured and target directional wave spectra are explored. By attempting to reproduce such challenging sea states, much has been learned about the limitations of simulating real ocean waves in a multidirectional wave basin, and about techniques which can be used to minimize the associated distortions to the directional spectrum.

Generation of a spatially periodic directional wave field in a rectangular wave basin based on higher-order spectral simulation

2018 ◽  
Vol 169 ◽  
pp. 428-441 ◽  
Author(s):  
Hidetaka Houtani ◽  
Takuji Waseda ◽  
Wataru Fujimoto ◽  
Keiji Kiyomatsu ◽  
Katsuji Tanizawa
Keyword(s):  
Wave Field ◽  
Higher Order ◽  
Spectral Simulation ◽  
Rectangular Wave ◽  
Wave Basin ◽  
Spatially Periodic ◽  
Directional Wave

On the Estimation of Directional Wave Spectrum Based on Stationary Vessels 1st Order Motions: A New Set of Experimental Results

2008 ◽  
Author(s):  
Joa˜o V. Sparano ◽  
Eduardo A. Tannuri ◽  
Alexandre N. Simos ◽  
Vini´cius L. F. Matos
Keyword(s):  
Bayesian Inference ◽  
Wave Spectrum ◽  
Small Scale ◽  
Large Set ◽  
Wave Spectra ◽  
Inference Method ◽  
Peak Period ◽  
Wave Basin ◽  
Bayesian Inference Method ◽  
Directional Wave

The practicability of estimating directional wave spectra based on a vessel 1st order response has been recently addressed by several researchers. The interest is justified since on-board estimations would only require only a simple set of accelerometers and rate-gyros connected to an ordinary PC. The on-board wave inference based on 1st order motions is therefore an uncomplicated and inexpensive choice for wave estimation if compared to wave buoys and radar systems. The latest works in the field indicate that it is indeed possible to obtain accurate estimations and a Bayesian inference model seems to be the preferable method adopted for performing this task. Nevertheless, most of the previous analysis has been based exclusively on numerical simulations. At Polytechnic School, an extensive research program supported by Petrobras has been conducted since 2000, aiming to evaluate the possibility of estimating wave spectrum on-board offshore systems, like FPSO platforms. In this context, a series of small-scale tests has been performed at the LabOceano wave basin, comprising long and short crested seas. A possible candidate for on-board wave estimation has been recently studied: a crane barge (BGL) used for launching ducts offshore Brazil. The 1:48 model has been subjected to bow and quartering seas with different wave heights and periods and also different levels of directional spreading. A Bayesian inference method was adopted for evaluating the wave spectra based on the time-series of motions and the results were directly compared to the wave spectra measured in the basin by means of an array of wave probes. Very good estimations of the statistical parameters (significant wave height, peak period and mean wave direction) were obtained and, in most cases, even the directional spreading could be properly predicted. Inversion of the mean direction (180° shift), mentioned by some authors as a possible drawback of the Bayesian inference method, was not observed in any case. Sensitivity analysis on errors in the input parameters, such as the vessel inertial characteristics, has also been performed and attested that the method is robust enough to cope well with practical uncertainties. Overall results once again indicate a good performance of the inference method, providing an important additional validation supported by a large set of model tests.

Freak Wave Generation in a Wave Basin With HOSM-WG Method

2015 ◽  
Author(s):  
Hidetaka Houtani ◽  
Takuji Waseda ◽  
Wataru Fujimoto ◽  
Keiji Kiyomatsu ◽  
Katsuji Tanizawa
Keyword(s):  
Control Method ◽  
Irregular Waves ◽  
Frequency Bandwidth ◽  
Freak Waves ◽  
Freak Wave ◽  
Wave Basin ◽  
Wave Trains ◽  
Directional Wave ◽  
Wave Maker ◽  
The Difference

A method to produce freak waves with arbitrary spectrum in a fully directional wave basin is presented here. This is an extension of Waseda, Houtani and Tanizawa at OMAE 2013[1], which used “HOSM-WG” based on the higher-order spectral method (HOSM). We used the following three methods to improve the HOSM-WG in [1]: “separation of free waves from bound waves,” “using Biesel’s transfer function in wavenumber space” and “using Schaffer’s 2nd-order wave maker control method.” Modulational wave trains, freak waves in unidirectional irregular waves and freak waves in short-crested irregular waves were generated in a wave basin. The experimental results using the improved HOSM-WG were compared to the HOSM simulation, and good agreements were found. The effectiveness of the improved HOSM-WG was ascertained. We showed that the difference between HOSM-WG and HOSM simulations became larger as wave steepness, frequency bandwidth of the spectrum or directional spreading became larger.

A Methodology for the Analysis of Physical Model Scale Effects on the Simulation of Wave Propagation up to Wave Breaking: Preliminary Physical Model Results

2008 ◽  
Author(s):  
Conceic¸a˜o Fortes ◽  
Maria da Grac¸a Neves ◽  
Joa˜o Alfredo Santos ◽  
Rui Capita˜o ◽  
Artur Palha ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Physical Model ◽  
Scale Effects ◽  
National Laboratory ◽  
Physical Models ◽  
Type Model ◽  
Research Activity ◽  
Joint Research ◽  
Common Structure ◽  
Constant Slope

This paper describes the experiments performed at the National Laboratory for Civil Engineering (LNEC) aiming at simulating, in a flume, the wave propagation along a constant slope bottom that ends on a sea wall coastal defence structure, a common structure employed in the Portuguese coast. The objective of these tests is to calibrate the parameters of FUNWAVE, a Boussinesq type model, for wave propagation in coastal regions. This is the first step in the validation of a methodology to combine numerical and physical models in the study of the interactions between beaches and structures. This work is performed in the framework of the Composite Modelling of the Interactions between Beaches and Structures (CoMIBBs) project, a joint research activity of the HYDRALAB III European project.

scholarly journals Dynamic Behaviour of the Loads of Podded Propellers in Waves: Experimental and Numerical Simulations

2014 ◽  
Author(s):  
Patrick Queutey ◽  
Jeroen Wackers ◽  
Alban Leroyer ◽  
GanBo Deng ◽  
Emmanuel Guilmineau ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Stokes Equations ◽  
Scale Effects ◽  
Computational Study ◽  
Essential Feature ◽  
Flow Distribution ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Flow Solver ◽  
Wave Basin

The paper focuses on the hydrodynamic flow around a ship with pods in waves and compares the results of an experimental campaign with numerical simulations conducted during the EU-funded STREAMLINE project. It was the first project for which the effect of waves on cavitation and ventilation was explored in both experimental and numerical ways for a ship with pods. The measurements were carried out in MARIN’s Depressurized Wave Basin (DWB) with a fully instrumented podded ship model, in sailing condition, in waves and depressurised conditions. In this way, the correct representation of cavitation and possible ventilation bubbles and vortices is ensured, resulting in a correct physical behaviour. The discretisation of the Reynolds-Averaged Navier-Stokes Equations (RANSE) is based on the unstructured finite-volume flow solver ISIS-CFD developed by ECN-CNRS. An essential feature for full RANSE simulations with this code is the use of a sliding grid technique to simulate the real propeller rotating behind a ship hull. The computational study in operational service conditions considered here has been conducted to evaluate the instantaneous flow distribution around the podded propellers and to analyse and to compare the unsteady behaviour of the forces induced by the rotating propeller in waves with the measurements from omnidirectional propeller loads as well as the blade forces and moments. The computational study has been done in model and full scale to evaluate the scale effects.

A Laboratory Study on the Wave Distribution around Breakwater

2012 ◽  
Vol 170-173 ◽  
pp. 2312-2315 ◽  
Author(s):  
Bao Lei Geng ◽  
Ci Heng Zhang ◽  
Yu Fen Cao
Keyword(s):  
Physical Model ◽  
Laboratory Study ◽  
Incident Wave ◽  
Three Dimensional ◽  
Model Tests ◽  
Wave Action ◽  
Wave Basin ◽  
Wave Generator ◽  
Wave Distribution ◽  
Directional Wave

A three-dimensional physical model was used to study the wave distribution around breakwater in Malaysia Kuantan. Model tests were carried out by using the L-type action absorption directional wave generator in a 45m×40m wave basin at TIWTE in Tianjin China. The incident wave conditions were checked first in the laboratory and a series steps were introduced to construct the bathymetry and breakwater structure. At last, the wave distribution around the breakwater with 60yrs and 100yrs wave action were given respectively. The conclusions should be used to achieve optimization of the design.

scholarly journals CEOHYDRAULIC INVESTIGATIONS OF RUBBLE MOUND BREAKWATERS

1988 ◽  
Vol 1 (21) ◽  
pp. 166 ◽  
Author(s):  
W. Burger ◽  
H. Oumeraci ◽  
H.W. Partenscky
Keyword(s):  
Pore Pressure ◽  
Scale Effects ◽  
Numerical Models ◽  
Model Tests ◽  
Physical Models ◽  
Core Material ◽  
Scale Model ◽  
Small Scale ◽  
Rubble Mound ◽  
Rubble Mound Breakwaters

Due to the increase of ship sizes in recent decades a number of harbours and terminals have been built in deeper waters. Accordingly, the structures which have to provide protection against wave action become higher, too. In most cases, these protective structures are of the rubble mound type. Under such conditions the flow induced by waves within the breakwater and the related geotechnical behaviour of the rubble mound fill become more significant fcr the overall stability and should be considered in the design. In addition, it is known that the scales usually adopted in hydraulic models (1:30 to 1:60) for investigating the stability of large rubble mound breakwaters generally lead to scale effects with respect to the flow field inside the breakwater. This means that small-scale model tests are not appropriate for investigating the internal flow patterns or for evaluating the pore pressure field induced by the incident waves in,the core material. because of the uncontrolled conditions in the prototype, and since the actual permeability of the prototype rubble mound fill cannot be predicted (segregation, settlement, variation in grading, etc.), the use of large-scale physical models seems to be the most promising method for basic investigations of this kind. Moreover, the results of such largescale model tests may be used to validate the usual smaller scale models and to calibrate numerical models. Therefore, it is one of the objectives of our research programme on rubble mound breakwaters, which started in 1987, to concentrate on the evaluation of the wave-induced flow and pore pressure distribution within the breakwater.

Three Dimensional Physical Model Study on Penang Fishing Port Project

2014 ◽  
Vol 580-583 ◽  
pp. 2198-2201
Author(s):  
Ci Heng Zhang ◽  
Bao Lei Geng
Keyword(s):  
Physical Model ◽  
Incident Wave ◽  
Three Dimensional ◽  
Model Tests ◽  
Test Results ◽  
Model Study ◽  
Wave Basin ◽  
Wave Generator ◽  
Wave Distribution ◽  
Directional Wave

A three-dimensional physical model was used to study the wave distribution around breakwater in Malaysia Penang. Model tests were carried out by using the L-type action absorption directional wave generator in a 45m×40m wave basin at TIWTE in Tianjin China. The incident wave conditions were checked first in the laboratory and a series steps were introduced to construct the bathymetry and breakwater structure. By comparing the test results, the improved top elevation of breakwater is +4.5m, and the recommendation length of northern part of breakwater is 65m.

scholarly journals First Molecular Characterization of Colletotrichum sp. and Fusarium sp. Isolated from Mangrove in Mexico and the Antagonist Effect of Trichoderma harzianum as an Effective Biocontrol Agent

2021 ◽  
Vol 37 (5) ◽  
pp. 465-475
Author(s):  
Mayra I. Grano-Maldonado ◽  
Rosalio Ramos-Payan ◽  
Fernando Rivera-Chaparro ◽  
Maribel Aguilar-Medina ◽  
José Geovanni Romero-Quintana ◽  
...  
Keyword(s):  
Trichoderma Harzianum ◽  
Pathogenic Fungus ◽  
Mangifera Indica ◽  
Fungal Species ◽  
Avicennia Germinans ◽  
Molecular Characteristics ◽  
Mangrove Species ◽  
Southern Mexico ◽  
Red Mangrove ◽  
Fusarium Sp

The aim of this study was to characterize potential fungal species affecting mangrove species in Mexico. The phytopathogens were identified based on morphological and molecular characteristics using internal transcribed spacer (ITS1/ITS4) primers then sequenced and compared with the other related sequences in GenBank (NCBI). Three fungal species were identified as <i>Colletotrichum queenslandicum</i> (Weir and Johnst, 2012) from black mangrove (<i>Avicennia germinans</i>); <i>Colletotrichum ti</i> (Weir and Johnst, 2012) from white mangrove (<i>Laguncularia racemosa</i>) and buttonwood mangrove (<i>Conocarpus erectus</i>); <i>Fusarium equiseti</i> (Corda) from red mangrove (<i>Rhizophora mangle</i>). In addition, <i>C. ti</i> and <i>F. equiseti</i> were identified from mango <i>Mangifera indica</i> L. sampled close by the mangrove area. This study provides first evidence of anthracnose on four mangrove species caused by <i>Colletotrichum</i> and <i>Fusarium</i> species in the “Términos” coastal lagoon in Campeche State southern Mexico. This is the first time that <i>C. queenslandicum</i> and <i>C. ti</i> are reported in Mexico. <i>F. equiseti</i> has not been reported affecting <i>M. indica</i> and <i>R. mangle</i> until the present work. Little is known regarding fungal diseases affecting mangroves in Mexico. These ecosystems are protected by Mexican laws and may be threatened by these pathogenic fungus. This is the first report of the effect of <i>Trichoderma harzianum</i> TRICHO-SIN as an effective biological control against of <i>Colletotrichum</i> and <i>Fusarium</i> species.

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