scholarly journals CHANGES IN HEIGHT OP SHORT WAVES ON LONG WAVES

1978 ◽  
Vol 1 (16) ◽  
pp. 22
Author(s):  
Michio Sato ◽  
Kazuo Nakamura
Keyword(s):  
Experimental Study ◽  
Exact Solution ◽  
Gravity Waves ◽  
Approximate Expression ◽  
Long Waves ◽  
Experimental Results ◽  
Wave Flume ◽  
Short Waves

In this paper we describe an experimental study on changes in height of short gravity waves on long waves. Experiments were conducted by making mechanically generated long waves superpose on mechanically generated short waves in a wave flume of 30m long and lm wide. Exact solution by Longuet-Higgins and Stewart explained our experimental results, but approximate expression a'= a,(l+P) which is widely accepted seemed to be inadequate to explain our results.

The Propagation of Compressional Waves in a Dispersive Elastic Rod: Part II—Experimental Results and Comparison With Theory

1957 ◽  
Vol 24 (2) ◽  
pp. 240-244
Author(s):  
Julius Miklowitz ◽  
C. R. Nisewanger
Keyword(s):  
Shock Tube ◽  
Longitudinal Mode ◽  
Long Waves ◽  
Experimental Results ◽  
Radial Mode ◽  
Approximate Representation ◽  
Elastic Rod ◽  
Compressional Waves ◽  
Short Waves

Abstract Experimental results, obtained by employing an aerodynamic shock tube for rod excitation, are presented. Comparison of these results with the theoretical information presented in Part I is made. It is shown that the Mindlin-Herrmann theory, through its upper mode (radial), offers a good approximate representation of the moderately short waves that predominate at the later times at a random station of the rod. The very short waves of this same radial mode, however, govern the early disturbance, thus precluding the possibility of representing this portion of the disturbance, which the experiment shows to be composed of relatively long waves, by the longitudinal mode of the theory.

scholarly journals The modulation of short gravity waves by long waves or currents

1988 ◽  
Vol 29 (4) ◽  
pp. 410-429 ◽  
Author(s):  
R. Grimshaw
Keyword(s):  
Gravity Waves ◽  
Finite Amplitude ◽  
Basic Flow ◽  
Long Waves ◽  
Water Current ◽  
Kinematic Equation ◽  
Local Dispersion ◽  
Short Waves ◽  
First Case ◽  
A Current

AbstractThe modulation of short gravity waves by long waves or currents is described for the situation when the flow is irrotational and when the short waves are described by linearised equations. Two cases are distinguished depending on whether the basic flow can be characterised as a deep-water current, or a shallow-water current. In both cases the basic flow has a current which has finite amplitude, while in the first case the free surface slope of the basic flow can be finite, but in the second case is small. The modulation equations are the local dispersion relation of the short waves, the kinematic equation for conservation of wave crests and the wave action equation. The results incorporate and extend the earlier work of Longuet-Higgins and Stewart [10, 11].

scholarly journals On the mass and momentum transfer between short gravity waves and larger-scale motions

1971 ◽  
Vol 50 (1) ◽  
pp. 189-205 ◽  
Author(s):  
K. Hasselmann
Keyword(s):  
Mass Transfer ◽  
Gravity Waves ◽  
Cross Sections ◽  
Residual Energy ◽  
Long Waves ◽  
Mean Flow ◽  
Surface Mass ◽  
Short Waves ◽  
Surface Mass Transfer ◽  
Order Of Magnitude

Interactions between short gravity waves and larger-scale flows are investigated in the two-scale approximation. The effect of the wave field on the mean flow is described by an interaction stress tensor and a surface mass transfer. The results are applied to Phillips’ and Longuet-Higgins’ model of short waves breaking on the crests of long carrier waves. It is found that the work done on the long waves by the interaction stresses (corresponding to Longuet-Higgins’ ‘maser’ mechanism of wave generation) is almost exactly balanced by the loss of potential energy arising from the mass transfer. The residual energy transfer leads to attenuation of the long waves, independent of their propagation direction relative to the short waves. Damping factors are estimated from the upwind–downwind ratios of radar backscatter cross-sections. It is found that interactions with waves shorter than 35cm yield attenuation rates about an order of magnitude smaller than the observed growth rates due to the wind.

An instability of internal gravity waves

1972 ◽  
Vol 52 (2) ◽  
pp. 393-399 ◽  
Author(s):  
Ronald Smith
Keyword(s):  
Surface Wave ◽  
Internal Wave ◽  
Surface Waves ◽  
Gravity Waves ◽  
Internal Gravity Waves ◽  
Long Waves ◽  
Wave Number ◽  
Short Waves

When water is slightly stratified, internal gravity waves are considerably shorter than surface waves of comparable frequency. Here, this fact is exploited in demonstrating that an internal wave is unstable when it forms part of a resonant triad with a surface wave and another internal wave whose wave number is approximately equal to that of the original internal wave. It is suggested that in a system where there are two classes of waves of comparable frequencies but greatly differing wavelengths the short waves may be expected to generate long waves by this mechanism.

Experimental Study on the Effect of Macroroughness on Tsunami Flow and Loading of Building

2015 ◽  
Vol 802 ◽  
pp. 190-195 ◽  
Author(s):  
Wei Chek Moon ◽  
Lerk Qing Chiew ◽  
Kah Win Cheong ◽  
Yi Cong Tee ◽  
Jan Bong Chun ◽  
...  
Keyword(s):  
Experimental Study ◽  
Wave Height ◽  
Experimental Results ◽  
Front Face ◽  
High Solid ◽  
Wave Flume ◽  
Building Model ◽  
Long Wave ◽  
Back Face ◽  
Sheltering Effect

This study experimentally investigated the effect of nearby buildings, termed macroroughness on the tsunami loading. The hydraulic experiment was conducted in a 1 m x 1 m with 40 m long wave flume at a scale of 1:100. Nominal wave height of 40 mm was simulated in this study. Both the building model and the macroroughness elements consisted of 66 mm high solid blocks. Wave pressures exerted on frontal and back faces of the building model were discussed in detail in this paper. Experimental results showed that the macroroughness elements had a significant impact on tsunami loading in the inundation zone. Sheltering effect was exhibited by the seaward macroroughness elements, showing significant reduction in the front face pressures. With the presence of the landward macroroughness elements, the wave pressures at the back face of the building model increased significantly at the initial impact.

scholarly journals Experimental study of the $ \gamma p \rightarrow K^{0}\Sigma^{+}$, $ \gamma n \rightarrow K^{0} \Lambda$, and $ \gamma n \rightarrow K^{0} \Sigma^{0}$ reactions at the Mainz Microtron

2019 ◽  
Vol 55 (11) ◽  
Author(s):  
C. S. Akondi ◽  
K. Bantawa ◽  
D. M. Manley ◽  
S. Abt ◽  
P. Achenbach ◽  
...  
Keyword(s):  
Experimental Study ◽  
Cross Sections ◽  
Differential Cross ◽  
Legendre Polynomials ◽  
Neutral Kaon ◽  
Experimental Results ◽  
Differential Cross Sections ◽  
Theoretical Predictions ◽  
Photoproduction Reactions ◽  
Insight Into

Abstract.This work measured $ \mathrm{d}\sigma/\mathrm{d}\Omega$dσ/dΩ for neutral kaon photoproduction reactions from threshold up to a c.m. energy of 1855MeV, focussing specifically on the $ \gamma p\rightarrow K^0\Sigma^+$γp→K0Σ+, $ \gamma n\rightarrow K^0\Lambda$γn→K0Λ, and $ \gamma n\rightarrow K^0 \Sigma^0$γn→K0Σ0 reactions. Our results for $ \gamma n\rightarrow K^0 \Sigma^0$γn→K0Σ0 are the first-ever measurements for that reaction. These data will provide insight into the properties of $ N^{\ast}$N* resonances and, in particular, will lead to an improved knowledge about those states that couple only weakly to the $ \pi N$πN channel. Integrated cross sections were extracted by fitting the differential cross sections for each reaction as a series of Legendre polynomials and our results are compared with prior experimental results and theoretical predictions.

scholarly journals Numerical and experimental study of the dynamic factor of the dynamic load on the urban railway

2020 ◽  
Vol 29 (1) ◽  
pp. 195-202
Author(s):  
Tran Anh Dung ◽  
Mai Van Tham ◽  
Do Xuan Quy ◽  
Tran The Truyen ◽  
Pham Van Ky ◽  
...  
Keyword(s):  
Experimental Study ◽  
Dynamic Load ◽  
Dynamic Measurement ◽  
Experimental Results ◽  
Load Factor ◽  
Dynamic Factor ◽  
Experimental Measurements ◽  
Train Speed ◽  
Dynamic Load Factor

AbstractThis paper presents simulation calculations and experimental measurements to determine the dynamic load factor (DLF) of train on the urban railway in Vietnam. Simulation calculations are performed by SIMPACK software. Dynamic measurement experiments were conducted on Cat Linh – Ha Dong line. The simulation and experimental results provide the DLF values with the largest difference of 2.46% when the train speed varies from 0 km/h to 80 km/h

Experimental Study of a Tanker Ship Squat in Shallow Water

2014 ◽  
Vol 66 (2) ◽  
Author(s):  
Mohammadreza Fathi Kazerooni ◽  
Mohammad Saeed Seif
Keyword(s):  
Experimental Study ◽  
Shallow Water ◽  
Experimental Approach ◽  
Model Tests ◽  
Ship Hull ◽  
Experimental Results ◽  
Shallow Waters ◽  
Towing Tank ◽  
Ship Model

One of the phenomena restricting the tanker navigation in shallow waters is reduction of under keel clearance in the terms of sinkage and dynamic trim that is called squatting. According to the complexity of flow around ship hull, one of the best methods to predict the ship squat is experimental approach based on model tests in the towing tank. In this study model tests for tanker ship model had been held in the towing tank and squat of the model are measured and analyzed. Based on experimental results suitable formulae for prediction of these types of ship squat in fairways are obtained.

Experimental Study on the Optimal Thickness of Infiltration Media of the CRI System

2011 ◽  
Vol 415-417 ◽  
pp. 1703-1707
Author(s):  
Jun Min Chen ◽  
Xiao Lin Yao
Keyword(s):  
Experimental Study ◽  
Removal Efficiency ◽  
Significant Influence ◽  
Soil Column ◽  
Experimental Results ◽  
Artificial Soil ◽  
Optimal Thickness ◽  
Effluent Quality ◽  
Anaerobic Zone

Abstract. In order to investigate the optimal thickness of infiltration media in the Constructed Rapid Infiltration System, the artificial soil column is used to simulate the Constructed Rapid Infiltration System, and the CODCr, NH3-N and TN concentrations of the effluent from all the sampling sites are monitored. The experimental results and analysis show that the thickness of infiltration media exerts a significant influence on the CODCr, NH3-N and TN concentration and removal efficiency of the effluent; the CODCr, NH3-N and TN are mainly removed in the 0-1800mm zone of the artificial soil column; the total CODCr removal efficiency increases, as the thickness of infiltration media increases, but the CODCr removal efficiency in the 1800-2200mm zone is very low; the NH3-N and TN removal efficiency reaches the maximum where the thickness of infiltration media is 1800mm; the NH3-N and TN concentration of the effluent from 1800-2200mm zone dose not decrease, but increase 5-8%, due to the assimilation denitrification and amemoniation reaction on the end of the anaerobic zone; in consideration of the effluent quality, efficient biodegradation zone, construction investment, etc. the optimal thickness of infiltration media in CRI system should be 1800mm.

scholarly journals Experimental study of water droplet break up in water in oil dispersions using an apparatus that produces localized pressure drops

2019 ◽  
Vol 74 ◽  
pp. 1 ◽  
Author(s):  
Fabricio S. Silva ◽  
Ricardo A. Medronho ◽  
Luiz Fernando Barca
Keyword(s):  
Experimental Study ◽  
Droplet Size Distribution ◽  
Energy Dissipation Rate ◽  
Experimental Results ◽  
Good Prediction ◽  
Pressure Drops ◽  
Turbulence Suppression ◽  
Kolmogorov Length Scale ◽  
Control Production ◽  
Break Up

Oil production facilities have choke/control valves to control production and protect downstream equipment against over pressurization. This process is responsible for droplets break up and the formation of emulsions which are difficult to treat. An experimental study of water in oil dispersion droplets break up in localized pressure drop is presented. To accomplish that, an apparatus simulating a gate valve was constructed. Droplet Size Distribution (DSD) was measured by laser light scattering. Oil physical properties were controlled and three different break up models were compared with the experimental results. All experimental maximum diameters (dmax) were above Kolmogorov length scale. The results show that dmax decreases with increase of energy dissipation rate (ε) according to the relation dmax ∝ ε−0.42. The Hinze (1955, AIChE J.1, 3, 289–295) model failed to predict the experimental results, although, it was able to adjust reasonably well those points when the original proportional constant was changed. It was observed that increasing the dispersed phase concentration increases dmax due to turbulence suppression and/or coalescence phenomenon. Turbulent viscous break up model gave fairly good prediction.

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