Comparison of Wave Run-Up Formulas by Flume Experiments

2014 ◽  
Vol 556-562 ◽  
pp. 4151-4154
Author(s):  
Lei Wang ◽  
Shou Xian Zhu ◽  
Xun Qiang Li ◽  
Wen Jing Zhang ◽  
Wen Chao Wang
Keyword(s):  
Significant Error ◽  
Flume Experiments ◽  
Mathematical Equations ◽  
Run Up ◽  
Steep Slopes ◽  
Good Agreement

The wave run-up formulas from the Code of Hydrology for Sea Harbour (CHSH), the Code for design of levee project (CDLP) and Hunt are all widely used, but they are in different forms of mathematical equations. In this paper, some flume experiments for wave run-up are made to examine these formulas. The tests show that the wave run-up formula from Hunt is in good agreement with the experiments. The wave run-up formula from CDLP has been usually used in steep slopes, while the tests show that it is also in good agreement with the experiments in the small slope flume. The wave run-up formula from CHSH is also used mainly in steep slopes, it brings significant error of the wave run-up calculation contrasting with the experiments.

scholarly journals DEVELOPMENT AND APPLICATION OF A MATHEMATICAL MODEL OF WAVE ACTION ON STEEP SLOPES

1988 ◽  
Vol 1 (21) ◽  
pp. 19
Author(s):  
N.W.H. Allsop ◽  
J.V. Smallman ◽  
R.V. Stephens
Keyword(s):  
Mathematical Model ◽  
Physical Model ◽  
Water Surface ◽  
Wave Action ◽  
Surface Elevation ◽  
Water Surface Elevation ◽  
Run Up ◽  
Steep Slopes ◽  
Good Agreement

This paper summaries the initial stages in the development of a mathematical model of wave action on slopes. The model calculates water surface elevation and depth averaged velocity on the slope, and uses this data to estimate the level of wave run-up. The model has been validated by comparing its results with those from similar models, and from a physical model. Examples are presented of these comparisons, which were found to be in good agreement in most cases.

Asymptotic modal approximation of nonlinear resonant sloshing in a rectangular tank with small fluid depth

2002 ◽  
Vol 470 ◽  
pp. 319-357 ◽  
Author(s):  
ODD M. FALTINSEN ◽  
ALEXANDER N. TIMOKHA
Keyword(s):  
Finite Depth ◽  
Modal System ◽  
Full Account ◽  
Inviscid Flows ◽  
State Response ◽  
Linear Damping ◽  
Convergence Problems ◽  
Run Up ◽  
Fourth Order Polynomial ◽  
Good Agreement

The modal system describing nonlinear sloshing with inviscid flows in a rectangular rigid tank is revised to match both shallow fluid and secondary (internal) resonance asymptotics. The main goal is to examine nonlinear resonant waves for intermediate depth/breadth ratio 0.1 [lsim ] h/l [lsim ] 0.24 forced by surge/pitch excitation with frequency in the vicinity of the lowest natural frequency. The revised modal equations take full account of nonlinearities up to fourth-order polynomial terms in generalized coordinates and h/l and may be treated as a modal Boussinesq-type theory. The system is truncated with a high number of modes and shows good agreement with experimental data by Rognebakke (1998) for transient motions, where previous finite depth modal theories failed. However, difficulties may occur when experiments show significant energy dissipation associated with run-up at the walls and wave breaking. After reviewing published results on damping rates for lower and higher modes, the linear damping terms due to the linear laminar boundary layer near the tank's surface and viscosity in the fluid bulk are incorporated. This improves the simulation of transient motions. The steady-state response agrees well with experiments by Chester & Bones (1968) for shallow water, and Abramson et al. (1974), Olsen & Johnsen (1975) for intermediate fluid depths. When h/l [lsim ] 0.05, convergence problems associated with increasing the dimension of the modal system are reported.

scholarly journals Statistics of Simulated Storm Waves over Bathymetry

2021 ◽  
Vol 9 (7) ◽  
pp. 784
Author(s):  
Arnida Lailatul Latifah ◽  
Durra Handri ◽  
Ayu Shabrina ◽  
Henokh Hariyanto ◽  
E. van Groesen
Keyword(s):  
Water Waves ◽  
Open Water ◽  
Storm Events ◽  
Extreme Waves ◽  
Marine Structures ◽  
Wave Statistics ◽  
Storm Waves ◽  
Different Types ◽  
Run Up ◽  
Good Agreement

This paper shows simulations of high waves over different bathymetries to collect statistical information, particularly kurtosis and crest exceedance, that quantifies the occurrence of exceptionally extreme waves. This knowledge is especially pertinent for the design and operation of marine structures, safe ship trafficking, and mooring strategies for ships near the coast. Taking advantage of the flexibility to perform numerical simulations with HAWASSI software, with the aim of investigating the physical and statistical properties for these cases, this paper investigates the change in wave statistics related to changes in depth, breaking and differences between long- and short-crested waves. Three different types of bathymetry are considered: run-up to the coast with slope 1/20, waves over a shoal, and deep open-water waves. Simulations show good agreement in the examined cases compared with the available experimental data and simulations. Then predictive simulations for cases with a higher significant wave height illustrate the changes that may occur during storm events.

scholarly journals Retrieval of snow grain size and albedo of Western Himalayan snow cover using satellite data

2011 ◽  
Vol 5 (1) ◽  
pp. 605-653 ◽  
Author(s):  
H. S. Negi ◽  
A. Kokhanovsky
Keyword(s):  
Grain Size ◽  
Snow Cover ◽  
Western Himalaya ◽  
Sensor Data ◽  
Art Theory ◽  
Grain Sizes ◽  
Spectral Bands ◽  
Steep Slopes ◽  
Different Parts ◽  
Good Agreement

Abstract. In the present study we describe the retrievals of snow grain size and spectral albedo (plane and spherical albedo) for Western Himalayan snow cover using Hyperion sensor data. The asymptotic radiative transfer (ART) theory was explored for the snow retrievals. To make the methodology operational only five spectral bands (440, 500, 1050, 1240 and 1650 nm) of Hyperion were used for snow parameters retrieval. The bi-spectral method (440 nm in the visible and 1050/1240 nm in the NIR region) was used to retrieve snow grain size. Spectral albedos were retrieved using satellite reflectances and estimated grain size. A good agreement was observed between retrieved snow parameters and ground observed snow-meteorological conditions. The satellite retrieved grain sizes were compared with field spectroradiometer retrieved grain sizes and close results were found for Lower Himalayan snow. The wavelength 1240 nm was found to be more suitable compared to 1050 nm for grain size retrieval along the steep slopes. The methodology was able to retrieve the spatial variations in snow parameters in different parts of Western Himalaya which are due to snow climatic and terrain conditions of Himalaya. This methodology is of importance for operational snow cover and glacier monitoring in Himalayan region using space-borne and air-borne sensors.

scholarly journals INTERACTION OF IDEALIZED URBAN INFRASTRUCTURE AND LONG WAVES DURING RUN-UP AND ON-LAND FLOW PROCESS IN COASTAL REGIONS

2012 ◽  
Vol 1 (33) ◽  
pp. 18 ◽  
Author(s):  
Nils Goseberg ◽  
Torsten Schlurmann
Keyword(s):  
Shock Wave ◽  
Urban Infrastructure ◽  
Coastal Regions ◽  
Flow Process ◽  
Long Wave ◽  
Roughness Elements ◽  
Shock Wave Generation ◽  
Run Up ◽  
Sloping Beach ◽  
Good Agreement

This paper reports experimental results of long wave run-up climbing up a 1:40 sloping beach. The resulting maximum run-up is compared with analytical results and a good agreement is found for single sinusoidal waves with uniform wave period and varying amplitude. Subsequently, the interaction with macro-roughness elements on the beach is investigated for different long-shore obstruction ratios. The reduction in wave run-up is expressed by means of a nomogram relating the wave run-up without macro-roughness elements present to those cases where on-land flow is modified by macro-roughness. The presented results mainly focus on a non-staggered and non-rotated macro-roughness configuration. In addition to the run-up reduction, surface elevation profiles on the shore are presented, that address the shock wave generation when the wave tongue approaches the first row of macro-roughness elements.

Modeling the flow around and the hydrodynamic drag on net meshes using REEF3D

2021 ◽  
pp. 1-21
Author(s):  
Gang Wang ◽  
Tobias Martin ◽  
Liuyi Huang ◽  
Hans Bihs
Keyword(s):  
Open Source ◽  
Empirical Formula ◽  
Hydrodynamic Forces ◽  
Hydrodynamic Drag ◽  
Hydrodynamic Coefficients ◽  
Flume Experiments ◽  
Simulation Accuracy ◽  
Flow Interactions ◽  
Fluid Properties ◽  
Good Agreement

Abstract The hydrodynamics and flow around net meshes has recently drawn more and more attention because it is closely related to the expected forces on aquaculture. In terms of modelling the hydrodynamic forces on nets, Morison or screen force models are ordinarily. However, they mainly rely on empirical, experimental or cylindrical hydrodynamic coefficients, neglecting the flow interactions between adjacent net twines. In this study, the open-source hydrodynamic toolbox REEF3D is adopted to analyze the flow around net meshes and investigate the hydrodynamic drag on the structure. The simulation accuracy is in good agreement with flume experiments and previous research. The results demonstrate that 2 × 2 or 3 × 3 mesh cases are more reliable for studying the flow around net meshes including the flow interactions around adjacent twines. It is further shown that controlling the solidity of the net through changing net bar diameters has different effects on the flow around meshes than controlling it by the twine length. This paper presents a first step in the aim to derive a new empirical formula for the drag coefficients depending on the solidity and fluid properties which is more appropriate for to the physics involved in offshore conditions.

scholarly journals Retrieval of snow grain size and albedo of western Himalayan snow cover using satellite data

2011 ◽  
Vol 5 (4) ◽  
pp. 831-847 ◽  
Author(s):  
H. S. Negi ◽  
A. Kokhanovsky
Keyword(s):  
Grain Size ◽  
Snow Cover ◽  
Western Himalaya ◽  
Sensor Data ◽  
Art Theory ◽  
Grain Sizes ◽  
Spectral Bands ◽  
Steep Slopes ◽  
Different Parts ◽  
Good Agreement

Abstract. In the present study we describe the retrievals of snow grain size and spectral albedo (plane and spherical albedo) for western Himalayan snow cover using Hyperion sensor data. The asymptotic radiative transfer (ART) theory was explored for the snow retrievals. To make the methodology operational only five spectral bands (440, 500, 1050, 1240 and 1650 nm) of Hyperion were used for snow parameters retrieval. The bi-spectral method (440 nm in the visible and 1050/1240 nm in the NIR region) was used to retrieve snow grain size. Spectral albedos were retrieved using satellite reflectances and estimated grain size. A good agreement was observed between retrieved snow parameters and ground observed snow-meteorological conditions. The satellite retrieved grain sizes were compared with field spectroradiometer retrieved grain sizes and close results were found for lower Himalayan snow. The wavelength 1240 nm was found to be more suitable compared to 1050 nm for grain size retrieval along the steep slopes. The methodology was able to retrieve the spatial variations in snow parameters in different parts of western Himalaya which are due to snow climatic and terrain conditions of Himalaya. This methodology is of importance for operational snow cover and glacier monitoring in Himalayan region using space-borne and air-borne sensors.

scholarly journals Nonlinear run-ups of regular waves on sloping structures

2012 ◽  
Vol 12 (12) ◽  
pp. 3811-3820 ◽  
Author(s):  
T.-W. Hsu ◽  
S.-J. Liang ◽  
B.-D. Young ◽  
S.-H. Ou
Keyword(s):  
Boussinesq Equations ◽  
Irregular Waves ◽  
Coastal Structures ◽  
Regular Waves ◽  
Wave Flume ◽  
Coastal Risk ◽  
Run Up ◽  
Two Parameters ◽  
Prediction Capability ◽  
Good Agreement

Abstract. For coastal risk mapping, it is extremely important to accurately predict wave run-ups since they influence overtopping calculations; however, nonlinear run-ups of regular waves on sloping structures are still not accurately modeled. We report the development of a high-order numerical model for regular waves based on the second-order nonlinear Boussinesq equations (BEs) derived by Wei et al. (1995). We calculated 160 cases of wave run-ups of nonlinear regular waves over various slope structures. Laboratory experiments were conducted in a wave flume for regular waves propagating over three plane slopes: tan α =1/5, 1/4, and 1/3. The numerical results, laboratory observations, as well as previous datasets were in good agreement. We have also proposed an empirical formula of the relative run-up in terms of two parameters: the Iribarren number ξ and sloping structures tan α. The prediction capability of the proposed formula was tested using previous data covering the range ξ ≤ 3 and 1/5 ≤ tan α ≤ 1/2 and found to be acceptable. Our study serves as a stepping stone to investigate run-up predictions for irregular waves and more complex geometries of coastal structures.

Three-Dimensional Numerical and Experimental Simulation of Wave Run-Up Due to Wave Impact With a Vertical Surface

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Armin Bodaghkhani ◽  
Yuri S. Muzychka ◽  
Bruce Colbourne
Keyword(s):  
Vertical Surface ◽  
The Body ◽  
Experimental Simulation ◽  
Processing Unit ◽  
Plate Model ◽  
Wave Impact ◽  
Central Processing ◽  
Break Up ◽  
Run Up ◽  
Good Agreement

This paper describes a numerical simulation of the interaction of a single nonlinear wave with a solid vertical surface in three dimensions. A coupled volume of fluid (VOF) and level set method (LSM) is used to simulate the wave-body interaction. A Cartesian-grid method is used to model immersed solid boundaries with constant grid spacing for simplicity and lower storage requirements. Mesh refinement is implemented near the wall boundaries due to the complex behavior of the free surface around the body. The behavior of the wave impact, the water sheet, and the high-speed jet arising from the wave impact are all captured with these methods. The numerical scheme is implemented using parallel computing due to the high central processing unit and memory requirements of this simulation. The maximum wave run-up velocity, instant wave run-up velocity in front of the vertical surface, the sheet break-up length, and the maximum impact pressure are computed for several input wave characteristics. Results are compared with a laboratory experiment that was carried out in a tow tank in which several generated waves were impacted with a fixed flat-shaped plate model. The numerical and experimental data on sheet breakup length are further compared with an analytical linear stability model for a viscous liquid sheet, and good agreement is achieved. The comparison between the numerical model and the experimental measurements of pressure, the wave run-up velocity, and the break-up length in front of the plate model shows good agreement.

scholarly journals WAVE RUN-UP OBSERVATIONS ON REVETMENTS WITH DIFFERENT POROSITIES

2012 ◽  
Vol 1 (33) ◽  
pp. 73 ◽  
Author(s):  
Stefan Schimmels ◽  
Michalis Vousdoukas ◽  
Dagmara Wziatek ◽  
Katharina Becker ◽  
Fabian Gier ◽  
...  
Keyword(s):  
Data Analysis ◽  
Concrete Block ◽  
Video Data ◽  
Coastal Protection ◽  
Large Wave ◽  
Wave Flume ◽  
New Type ◽  
Run Up ◽  
Highly Porous ◽  
Good Agreement

Wave run-up plays an important role in the design of coastal protection structures. However, none of the existing formulae for wave run-up predictions explicitly considers the effect of revetment porosity. Recently, two revetments have been tested in the Large Wave Flume (GWK) of Forschungszentrum Küste (FZK), a new type of highly porous polyurethane bonded (PBA revetment) revetment and a smooth interlocked pattern placed concrete block revetment (IPPB revetment), which is considered as “weakly permeable” for the present study. Wave run-up is evaluated by video data analysis based on timestack image processing. The results derived from the timestacks are compared to run-up data measured with conventional wire gauges and the good agreement demonstrates the accuracy and reliability of the video data analysis. The effect of the porosity of the revetment is incorporated into the EuroTop wave run-up formula, showing that for the present case it may reduce the relative run-up heights Ru,2%/Hm0 by about 25 % to 50 % as compared to a smooth impermeable slope.

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