EXPERIMENTAL INVESTIGATION ON BEACH MORPHODYNAMICAL PROCESS NEAR RIVER MOUTH

Physical model study on wave influences on river-mouth depositional process ispresented. Experiments were performed in a wave basin in order to determine erosionand accretion area due to the combined wave – current flows. An inflow glass channelwas designed to reproduce a river mouth model in a 3D wave basin made with a sandbottom. The tests were carried out under three different conditions: river current,waves, wave –current interaction. Measurements of wave heights, beach profiles andbathymetric profiles were made. The results show that in the presence of combinedwave-current flows, erosion areas are more evident in vicinity of a mouth with depthand width values greater than depth and width values of inflow channel.

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PHYSICAL MODELING STUDY ON SCOUR AND SCOUR COUNTERMEASURE FOR SEA-CROSSING BRIDGE PIERS

Coastal Engineering Proceedings ◽

10.9753/icce.v33.sediment.83 ◽

2012 ◽

Vol 1 (33) ◽

pp. 83

Author(s):

Hsin Hung Chen ◽

Ray-Yeng Yang ◽

Ping-Chiao Kuo ◽

Hwung-Hweng Hwung

Keyword(s):

Physical Model ◽

Model Tests ◽

Bridge Piers ◽

Test Series ◽

Model Study ◽

Sea Bed ◽

Wave Basin ◽

Scour Protection ◽

Hydraulics Laboratory ◽

Scour Countermeasure

There are significant engineering challenges in placing the sea-crossing bridge piers in more or les shallow coastal waters because, as well as having to withstand storm-force waves and tidal currents, the bridge piers have to remain stable on a sea bed that may be continuously changing. One of the major challenges faced by designers is how to predict, and prevent, scour of the seabed sediments around the sea-crossing bridge piers. This paper describes a physical model study on scour and scour countermeasure for sea-crossing bridge piers. A 1:49 scale movable bed model tests were carried out in the Near-shore Wave Basin (NSWB, 27m x 19m) at the Tainan Hydraulics Laboratory, National Chang Kung University (NCKU), Tainan, Taiwan, with the sea-crossing bridge piers in the test area. Three series of physical model tests were performed in this study. The aim of the first test series is to investigate the maximum scour depth for the initial construction of bridge piers with only one pier model. Then the second test series were conducted to investigate the greatest magnitude of local scour and potential scour area in the sand bed around the sea-crossing bridge group piers with no scour protection. Based on the analysis from the former NSWB experimental results, the suitable scour countermeasure for sea-crossing bridge piers would be proposed and validated its function of preventing scour in the third test series.

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CURRENT CHARACTERISTICS IN THE PRESENCE OF NEAR-ORTHOGONAL WAVES

Coastal Engineering Proceedings ◽

10.9753/icce.v33.currents.41 ◽

2012 ◽

Vol 1 (33) ◽

pp. 41

Author(s):

Kian Yew Lim ◽

Ole Secher Madsen ◽

Hin Fatt Cheong

Keyword(s):

Profile Analysis ◽

Numerical Study ◽

Flow Profile ◽

Wave Direction ◽

Mean Flow ◽

Wave Basin ◽

Current Interaction ◽

The Mean ◽

Current Flows ◽

Wave Induced

An experimental study involving near-orthogonal wave-current interaction in a wave basin is reported in this paper. Due to previous shortcomings associated with 2D bottom configurations, i.e. occurrence of ripple-induced turning of flows close to the bed, the present experiments were conducted with the bottom covered by closely packed ceramic marbles (mean diameter of 1.25cm). Three types of flows were generated over this bottom: current-alone, wave-alone and combined wave-current flow. For current-alone and wave-current cases, the log-profile analysis was used to resolve the equivalent Nikuradse sand grain roughness, kn, while the energy dissipation method was used to estimate kn for wave-alone case. The results show that kn obtained for current- and wave-alone tests is roughly 2.2 times the diameter of the marbles. For orthogonal wave-current flows, the kn value, when used in combination with the Grant-Madsen (GM) model to reproduce the experimental apparent roughness, is found to be smaller than the measured current-alone and wave-alone kn. Similar under-prediction of bottom roughness is also observed when the GM model is compared with a numerical study, thus supporting the conjecture that when the current is weak compared to the waves, simple theoretical models like GM are not sufficiently sensitive to the angle of wave-current interaction. Experiments with currents at angles of 60° and 120° to the wave direction yield apparent roughness smaller than the 90° case, which is counter-intuitive since one would expect the mean flow to experience a stronger wave-induced turbulence when it is more aligned with the wave direction. This result indicates a possible contamination from wave-induced mass transport to the mean flow profile for non-orthogonal combined flow cases, and therefore highlights the need for other alternatives to the log-profile analysis when attempting to resolve kn from current velocity profiles from combined wave-current flows.

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Three Dimensional Physical Model Study on Penang Fishing Port Project

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.580-583.2198 ◽

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.

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Model Study on the Key Hydrodynamics in the Bohai Sea

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.303-306.2727 ◽

2013 ◽

Vol 303-306 ◽

pp. 2727-2730 ◽

Cited By ~ 2

Author(s):

Hao Liu ◽

Dan Luo ◽

Bao Shu Yin

Keyword(s):

Bohai Sea ◽

Interaction Model ◽

Central Basin ◽

3 Dimensional ◽

The Bohai Sea ◽

Model Study ◽

Tidal Harmonic ◽

Wave Heights ◽

Current Interaction ◽

Wind Driven Currents

A surface wave and 3-dimensional current interaction model is used to reproduce the hydrodynamics in the Bohai Sea (BS). Simulated tidal harmonic constants, wind-driven currents and significant wave heights show reasonable agreements with observations. It is found that the semidiurnal tides are dominant by and large, and the maximum wave height appears in the central basin.

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Experimental Investigation of an Algorithm for Monitoring the State of Instrument Voltage Transformer Insulation on a Network Segment Physical Model

Vestnik MEI ◽

10.24160/1993-6982-2019-2-80-86 ◽

2019 ◽

Vol 2 (2) ◽

pp. 80-86

Author(s):

Vladimir M. Gevorkyan ◽

◽

Konstantin V. Krayushkin ◽

Keyword(s):

Experimental Investigation ◽

Physical Model ◽

The State ◽

Voltage Transformer ◽

Transformer Insulation

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Physical Model Study of Flowerpot Discharge Outlet, Western Closure Complex, New Orleans, Louisiana

10.21236/ada583046 ◽

2013 ◽

Author(s):

Stephen T. Maynord

Keyword(s):

New Orleans ◽

Physical Model ◽

Model Study

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Two-Dimensional Numerical Modeling of Flow in Physical Models of Rock Vane and Bendway Weir Configurations

Water ◽

10.3390/w13040458 ◽

2021 ◽

Vol 13 (4) ◽

pp. 458

Author(s):

Drew C. Baird ◽

Benjamin Abban ◽

S. Michael Scurlock ◽

Steven B. Abt ◽

Christopher I. Thornton

Keyword(s):

Numerical Modeling ◽

Physical Model ◽

Numerical Models ◽

Hydraulic Performance ◽

Physical Models ◽

Protection Measures ◽

Design Engineers ◽

Model Study ◽

Study Results ◽

Wide Range

While there are a wide range of design recommendations for using rock vanes and bendway weirs as streambank protection measures, no comprehensive, standard approach is currently available for design engineers to evaluate their hydraulic performance before construction. This study investigates using 2D numerical modeling as an option for predicting the hydraulic performance of rock vane and bendway weir structure designs for streambank protection. We used the Sedimentation and River Hydraulics (SRH)-2D depth-averaged numerical model to simulate flows around rock vane and bendway weir installations that were previously examined as part of a physical model study and that had water surface elevation and velocity observations. Overall, SRH-2D predicted the same general flow patterns as the physical model, but over- and underpredicted the flow velocity in some areas. These over- and underpredictions could be primarily attributed to the assumption of negligible vertical velocities. Nonetheless, the point differences between the predicted and observed velocities generally ranged from 15 to 25%, with some exceptions. The results showed that 2D numerical models could provide adequate insight into the hydraulic performance of rock vanes and bendway weirs. Accordingly, design guidance and implications of the study results are presented for design engineers.

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Experimental investigation on statistical properties of wave heights and crests in crossing sea conditions

Ocean Dynamics ◽

10.1007/s10236-015-0831-0 ◽

2015 ◽

Vol 65 (5) ◽

pp. 707-720 ◽

Cited By ~ 3

Author(s):

Alessandro D. Sabatino ◽

Marina Serio

Keyword(s):

Experimental Investigation ◽

Statistical Properties ◽

Wave Heights

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Canal Wave Oscillations from Expansion of I-84 Bridge in Boise, Idaho

Transportation Research Record Journal of the Transportation Research Board ◽

10.3141/2309-19 ◽

2012 ◽

Vol 2309 (1) ◽

pp. 200-205

Author(s):

William Rahmeyer ◽

J. M. Clegg ◽

S. L. Barfuss

Keyword(s):

New York ◽

Physical Model ◽

Unique Solution ◽

Wave Phenomenon ◽

Bridge Columns ◽

Bridge Abutments ◽

Wave Problem ◽

Model Study ◽

Bridge Crossing

Recent improvements and the widening of the I-84 Bridge crossing of the New York Canal in Boise, Idaho, have increased the number of bridge columns from 28 to 60. The resulting structure has two parallel rows of columns that extend across the width of the bridge longitudinally within the canal. After the widening of the bridge and addition of the bridge columns, the canal began experiencing an oscillating wave phenomenon that originated from the bridge columns and caused erosion of upstream and downstream canal banks and bridge abutments. A physical model study was conducted to investigate the wave phenomenon and determine what modifications to the columns or canal would be necessary to prevent the wave oscillations. The physical model was successful in simulating the wave phenomenon, and four different modifications for resolving the wave problem were tested in the model. A unique solution was found that used precast nose cones attached to selected columns. The nose cones have been installed in the prototype bridge crossing, and no wave oscillations have occurred since installation. This paper discusses the study to simulate the wave phenomenon and the four modifications that were evaluated to reduce or prevent wave oscillations.

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