scholarly journals WAVES OVERTOPPING A WIDE-CRESTED DIKE

2011 ◽  
Vol 1 (32) ◽  
pp. 7 ◽  
Author(s):  
Toon Verwaest ◽  
Philippe Vanpoucke ◽  
Marc Willems ◽  
Tom De Mulder
Keyword(s):  
Theoretical Model ◽  
Energy Balance ◽  
Kinetic Energy ◽  
Scale Model ◽  
Coastal Protection ◽  
Model Concept ◽  
Wave Overtopping ◽  
Model Research ◽  
Physical Scale ◽  
Semi Empirical

If a coastal dike has a crest width of more than say a few meters, then wave overtopping will be significantly reduced due to the crest width, because kinetic energy can be dissipated on the crest and water on the crest can flow back towards the seaside. In coastal towns built on dune belts often a wide-crested coastal dike was constructed as both coastal protection and sea promenade. However, quantifying the effect of such a wide crest on wave overtopping is not straightforward because no empirical overtopping formulas are given in literature for this kind of configuration. Therefore physical scale model research was carried out. Also a simplified theoretical model concept was used based on an energy balance formulation of a single overtopping wave. Combining the scale model measurements with the theoretical model, a semi-empirical formula was developed and calibrated.

scholarly journals HYDRODYNAMIC LOAD ON THE BUILDING CAUSED BY OVERTOPPING WAVES

2012 ◽  
Vol 1 (33) ◽  
pp. 59 ◽  
Author(s):  
Xuexue Chen ◽  
Wael Hassan ◽  
Wim Uijttewaal ◽  
Toon Verwaest ◽  
Henk Jan Verhagen ◽  
...  
Keyword(s):  
Kinetic Energy ◽  
Vertical Wall ◽  
Scale Model ◽  
Hydrodynamic Load ◽  
Empirical Formulas ◽  
Geometrical Characteristics ◽  
Wave Parameters ◽  
Model Research ◽  
Physical Scale ◽  
To Come

Wide crested dike can reduce the kinetic energy of the overtopping wave and make the overtopping wave to flow back to the seaside. If a coastal town were built on or near a dike, the overtopping wave running on the dike crest generates the force which can affect the buildings located in its path. However, quantifying the hydrodynamic load on the building caused by overtopping waves is not straightforward because little empirical formulas are given in literature for this kind of configuration. Therefore, physical scale model research was carried out. The purpose of this research is to come up with a relationship describing the force on a vertical wall exerted by the overtopping wave as a function of wave parameters and geometrical characteristics.

INTEGRATED DESIGN OF COASTAL PROTECTION WORKS FOR WENDUINE, BELGIUM

2012 ◽  
Vol 1 (33) ◽  
pp. 70 ◽  
Author(s):  
William Veale ◽  
Tomohiro Suzuki ◽  
Toon Verwaest ◽  
Koen Trouw ◽  
Tina Mertens
Keyword(s):  
Physical Model ◽  
Integrated Design ◽  
Low Frequency ◽  
Scale Model ◽  
Coastal Protection ◽  
New Wave ◽  
Wave Overtopping ◽  
Physical Model Tests ◽  
Physical Scale ◽  
Wave Basin

Wave overtopping tests were performed with a 1:25 physical scale model to determine the optimal geometry for design of new wave return walls at Wenduine, Belgium. Wave overtopping on the shallow foreshore at Wenduine was found to be dominated by low-frequency infragravity waves (f < 0.04 Hz at prototype scale). Mean wave overtopping discharge measured with the physical model compared well with the Van Gent (1999) empirical overtopping equations for shallow foreshores. Physical model tests confirmed that the stilling wave basin concept proposed by Geerearts, et al. (2006) and wave wall parapet concepts of van Doorslaer & De Rouck (2010) were effective at reducing the wave wall height required to meet the tolerable discharge overtopping standards.

scholarly journals Multiphasic Study of Fluid-Dynamics and the Thermal Behavior of a Steel Ladle during Bottom Gas Injection Using the Eulerian Model

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1082
Author(s):  
Antonio Urióstegui-Hernández ◽  
Pedro Garnica-González ◽  
José Ángel Ramos-Banderas ◽  
Constantin Alberto Hernández-Bocanegra ◽  
Gildardo Solorio-Díaz
Keyword(s):  
Heat Exchange ◽  
Thermal Behavior ◽  
Gas Flow ◽  
Fluid Dynamic ◽  
Steel Slag ◽  
Scale Model ◽  
Discrete Ordinates ◽  
Transfer Model ◽  
Steel Ladle ◽  
Physical Scale

In this work, the fluid dynamic and thermal behavior of steel was analyzed during argon gas stirring in a 140-t refining ladle. The Eulerian multiphase mathematical model was used in conjunction with the discrete ordinates (DO) thermal radiation model in a steel-slag-argon system. The model was validated by particle image velocimetry (PIV) and the analysis of the opening of the oil layer in a physical scale model. The effect of Al2O3 and Mg-C as a refractory in the walls was studied, and the Ranz-Marshall and Tomiyama models were compared to determine the heat exchange coefficient. The results indicated that there were no significant differences between these heat exchange models; likewise, the radiation heat transfer model adequately simulated the thermal behavior according to plant measurements, finding a thermal homogenization time of the steel of 2.5 min for a gas flow of 0.45 Nm3·min−1. Finally, both types of refractory kept the temperature of the steel within the ranges recommended in the plant; however, the use of Al2O3 had better heat retention, which would favor refining operations.

scholarly journals Roughness Lengths for Momentum and Heat Derived from Outdoor Urban Scale Models

2007 ◽  
Vol 46 (7) ◽  
pp. 1067-1079 ◽  
Author(s):  
M. Kanda ◽  
M. Kanega ◽  
T. Kawai ◽  
R. Moriwaki ◽  
H. Sugawara
Keyword(s):  
Wind Direction ◽  
Roughness Length ◽  
Scale Dependence ◽  
Scale Model ◽  
Small Scale ◽  
Physical Scale ◽  
Scale Models ◽  
Roughness Lengths ◽  
Urban Sites ◽  
Obstacle Height

Abstract Urban climate experimental results from the Comprehensive Outdoor Scale Model (COSMO) were used to estimate roughness lengths for momentum and heat. Two different physical scale models were used to investigate the scale dependence of the roughness lengths; the large scale model included an aligned array of 1.5-m concrete cubes, and the small scale model had a geometrically similar array of 0.15-m concrete cubes. Only turbulent data from the unstable boundary layers were considered. The roughness length for momentum relative to the obstacle height was dependent on wind direction, but the scale dependence was not evident. Estimated values agreed well with a conventional morphometric relationship. The logarithm of the roughness length for heat relative to the obstacle height depended on the scale but was insensitive to wind direction. COSMO data were used successfully to regress a theoretical relationship between κB−1, the logarithmic ratio of roughness length for momentum to heat, and Re*, the roughness Reynolds number. Values of κB−1 associated with Re* for three different urban sites from previous field experiments were intercompared. A surprising finding was that, even though surface geometry differed from site to site, the regressed function agreed with data from the three urban sites as well as with the COSMO data. Field data showed that κB−1 values decreased as the areal fraction of vegetation increased. The observed dependency of the bulk transfer coefficient on atmospheric stability in the COSMO data could be reproduced using the regressed function of Re* and κB−1, together with a Monin–Obukhov similarity framework.

AN EXPERIMENTAL STUDY ON THE RELATIVE MOTIONS BETWEEN A FLOATING HARBOUR TRANSHIPPER AND A FEEDER VESSEL IN REGULAR WAVES

2021 ◽  
Vol 154 (A2) ◽  
Author(s):  
G J Macfarlane ◽  
T Lilienthal ◽  
R J Ballantyne ◽  
S Ballantyne
Keyword(s):  
Open Water ◽  
Scale Model ◽  
Regular Waves ◽  
Inclement Weather ◽  
Port Operations ◽  
Physical Scale ◽  
Feeder Vessel ◽  
Primary Advantage ◽  
Exposed Location ◽  
Relative Motions

The Floating Harbour Transhipper (FHT) is a pioneering logistics solution that was designed to meet the growing demands for coastal transhipment in the mining sector as well as commercial port operations. The primary advantage of the FHT system is that it can reduce transhipment delays caused by inclement weather, by reducing relative motions between the FHT and feeder vessel. The feeder is sheltered when inside the FHT well dock when compared to the more exposed location when a feeder is in a traditional side-by-side mooring arrangement. This paper discusses previously published studies into the relative motions of vessels engaged in side-by-side mooring arrangements and also presents details and results from a series of physical scale model experiments. In these experiments, both side-by-side and aft well dock mooring arrangements are investigated. The results provide strong evidence that the FHT well dock concept can significantly reduce the heave, pitch and roll motions of feeder vessels when transhipping in open seas – this being the cornerstone of any successful open water transhipment operation.

The Force in a Die Forging Hammer

1983 ◽  
Vol 105 (4) ◽  
pp. 270-275 ◽  
Author(s):  
Hans W. Haller
Keyword(s):  
Plastic Deformation ◽  
Energy Balance ◽  
Kinetic Energy ◽  
Theoretical Prediction ◽  
Die Forging ◽  
Upper Limits ◽  
Hammer Forging

The blow of a die forging hammer in its nature and quantity is influenced by the behavior of the forging and its deformation status. In forging, the hammer supplies the energy necessary for plastic deformation as well as the force necessary to coin the forging. The main purpose of this paper is to determine, in hammer forging, how the forces are generated and how the hammer energy is transformed into energies (a) useful for deformation and (b) lost in vibration and noise. Theoretical prediction of the forces is possible by considering the energy balance between the kinetic energy of the ram and the energies used for deformation and lost in rebounding of the ram and the acceleration of the anvil. The results given in this paper show that it is possible to predict at least the upper limits of the generated forces for a given size of an anvil hammer.

Consistent Theoretical Model of Mean Diameter and Size Distribution by Liquid Sheet Atomization

2012 ◽  
Author(s):  
Chihiro Inoue ◽  
Toshinori Watanabe ◽  
Takehiro Himeno ◽  
Seiji Uzawa ◽  
Mitsuo Koshi
Keyword(s):  
Theoretical Model ◽  
Kinetic Energy ◽  
Droplet Diameter ◽  
Velocity Profiles ◽  
Liquid Sheet ◽  
Estimation Methods ◽  
Liquid Jets ◽  
Injection Velocity ◽  
Size Distributions ◽  
Mean Diameter

A consistent theoretical model is proposed and validated for calculating droplet diameters and size distributions. The model is derived based on the energy conservation law including the surface free energy and the Laplace pressure. Under several hypotheses, the law derives an equation indicating that atomization results from kinetic energy loss. Thus, once the amount of loss is determined, the droplet diameter is able to be calculated without the use of experimental parameters. When the effects of ambient gas are negligible, injection velocity profiles of liquid jets are the essential cause of the reduction of kinetic energy. The minimum Sauter mean diameter produced by liquid sheet atomization is inversely proportional to the injection Weber number when the injection velocity profiles are laminar or turbulent. A non-dimensional distribution function is also derived from the mean diameter model and Nukiyama-Tanasawa’s function. The new estimation methods are favorably validated by comparing with corresponding mean diameters and the size distributions, which are experimentally measured under atmospheric pressure.

Excited-state localization and energy transfer in pyrene core dendrimers with fluorene/carbazole as the dendrons and acetylene as the linkages

2016 ◽  
Vol 18 (5) ◽  
pp. 4134-4143 ◽  
Author(s):  
Linyin Yan ◽  
Yan Wan ◽  
Andong Xia ◽  
Sheng Hien Lin ◽  
Ran Huang
Keyword(s):  
Energy Transfer ◽  
Excited State ◽  
Theoretical Model ◽  
Empirical Methods ◽  
Multi Scale ◽  
Td Dft ◽  
Semi Empirical

Multi-scale theoretical model and spectra simulation for dendrimers combining TD-DFT/DFT and semi-empirical methods.

A Model for Calculating the Outlet Flue Gas Temperature of FGD Absorption Tower

2011 ◽  
Vol 130-134 ◽  
pp. 3812-3816
Author(s):  
Gang Xu ◽  
Yao Tian ◽  
Xing Yuan ◽  
Yong Ping Yang
Keyword(s):  
Theoretical Model ◽  
Energy Balance ◽  
Water Consumption ◽  
Flue Gas ◽  
Flue Gas Desulfurization ◽  
Gas Temperature ◽  
Significance Analysis

Theoretical model for calculating the outlet flue gas temperature of limestone-gypsum wet flue gas desulfurization (FGD) absorption tower is important for water consumption calculation. In this paper, the energy balance in the spray zone is analyzed and a model for calculating the outlet flue gas temperature of FGD absorption tower is proposed. An example computation of the outlet flue gas temperature of a typical 600MW class unit’s operation data is introduced, the result has verified the model. A further study of significance analysis has then been made to analyze and simplify the model.

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