scholarly journals A typical wave wake from high-speed vessels: its group structure and run-up

2013 ◽  
Vol 20 (1) ◽  
pp. 179-188 ◽  
Author(s):  
I. Didenkulova ◽  
A. Rodin
Keyword(s):  
Weibull Distribution ◽  
Water Waves ◽  
High Speed ◽  
Group Structure ◽  
High Amplitude ◽  
Beach Erosion ◽  
Strong Impact ◽  
Wave Heights ◽  
Run Up ◽  
The Baltic

Abstract. High-amplitude water waves induced by high-speed vessels are regularly observed in Tallinn Bay, the Baltic Sea, causing intense beach erosion and disturbing marine habitants in the coastal zone. Such a strong impact on the coast may be a result of a certain group structure of the wave wake. In order to understand it, here we present an experimental study of the group structure of these wakes at Pikakari beach, Tallinn Bay. The most energetic vessel waves at this location (100 m from the coast at the water depth 2.7 m) have amplitudes of about 1 m and periods of 8–10 s and cause maximum run-up heights on a beach up to 1.4 m. These waves represent frequency modulated packets where the largest and longest waves propagate ahead of other smaller amplitude and period waves. Sometimes the groups of different heights and periods can be separated even within one wave wake event. The wave heights within a wake are well described by the Weibull distribution, which has different parameters for wakes from different vessels. Wave run-up heights can also be described by Weibull distribution and its parameters can be connected to the parameters of the distribution of wave heights 100 m from the coast. Finally, the run-up of individual waves within a packet is studied. It is shown that the specific structure of frequency modulated wave packets, induced by high-speed vessels, leads to a sequence of high wave run-ups at the coast, even when the original wave heights are rather moderate. This feature can be a key to understanding the significant impact on coasts caused by fast vessels.

scholarly journals Variability in spatial patterns of long nonlinear waves from fast ferries in Tallinn Bay

2009 ◽  
Vol 16 (2) ◽  
pp. 351-363 ◽  
Author(s):  
T. Torsvik ◽  
I. Didenkulova ◽  
T. Soomere ◽  
K. E. Parnell
Keyword(s):  
High Speed ◽  
Wave Loads ◽  
S Waves ◽  
Ship Wave ◽  
Wake Patterns ◽  
Ship Wakes ◽  
Wave Heights ◽  
The Baltic ◽  
Sea Area ◽  
Intrinsic Feature

Abstract. High-speed ferries are known to generate wakes with unusually long periods, and occasionally large amplitudes which may serve as a qualitatively new forcing factor in coastal regions that are not exposed to a sea swell. An intrinsic feature of such wakes is their large spatial variation. We analyze the variability of wake conditions for the coasts of Tallinn Bay, the Baltic Sea, a sea area with very intense fast ferry traffic. The modelled ship wave properties for several GPS-recorded ship tracks reasonably match the measured waves in terms of both wave heights and periods. It is shown that the spatial extent of the wake patterns is very sensitive to small variations in sailing conditions. This feature leads to large variations of ship wave loads at different coastal sections with several locations regularly receiving high ship wave energy. The runup of the largest ship wakes on the beach increases significantly with an increase in wave height whereas shorter (period <2–5 s) waves merge into longer waves in the shoaling and runup process.

scholarly journals THE ASH WEDNESDAY EAST COAST STORM, MARCH 5-8, 1962 A HINDCAST OF EVENTS, CAUSES, AND EFFECTS

1964 ◽  
Vol 1 (9) ◽  
pp. 41
Author(s):  
Charles L. Bretschneider
Keyword(s):  
Storm Surge ◽  
Water Waves ◽  
East Coast ◽  
Time History ◽  
Beach Erosion ◽  
Wind Speeds ◽  
Recorded Data ◽  
Run Up ◽  
Over The Top ◽  
Gust Factors

Hmdcasts were made for winds, waves and tides for several east coast locations for the storm of 5-8 March 1962. A limited amount of recorded data and a considerable amount of other observations were available from near-by and remote stations. The data were analyzed for correlation or "calibration" purposes m order to improve the "state of the art" of wave and storm surge hindcastmg for locations where recorded data were not available. Wind records were analyzed to obtain sustained wind speeds, average gust factors, and probability distribution of gust factors. Isobaric patterns were used to determine sustained wind speeds over the water fetch for deep and shallow water waves and storm surge hmdcasts. Wave run-up calculations were made to determine the wave activity on the beach and the dunes and -were used to estimate the probable rate of beach erosion and dune evolution. The off-water wind speeds were modified to determine wind speeds over the beach and over the top of the dunes. Finally, by summarizing the time-history of the various meteorological, oceanographic, and coastal engineering events, a very interesting scientific and engineering evaluation of the causes and effects can be made.

COMPARATIVE ANALYSIS OF THE INFLUENCE OF NATURAL AND ANTHROPOGENIC FACTORS ON THE VISTULA SPIT FOREDUNE EROSION (THE BALTIC SEA

2017 ◽  
Author(s):  
Evgenii Burnashov ◽  
Evgenii Burnashov ◽  
Konstantin Karmanov ◽  
Konstantin Karmanov
Keyword(s):  
Baltic Sea ◽  
Laser Scanning ◽  
Essential Element ◽  
Base Station ◽  
Beach Erosion ◽  
Single Frequency ◽  
Anthropogenic Factors ◽  
The Baltic Sea ◽  
Volume Deformation ◽  
The Baltic

The study gives quantitative estimation of natural landforms sensitivity of accumulative type coasts exposed to human influence. Foredune is an essential element of a morphological structure of thebarrier spits located at the Baltic Sea sand coasts. The study compares contribution of the beach erosion and deflation (soil drifting) to the foredune degradation on the sea shore of the barrier spit with or without the recreational impact. The analysis is performed for three typical polygons located on the Russian part of the Vistula Spit. Chosen polygons present shore segments with various intensity of tourism: visitors from the village, unregulated camp tourism, and nearly natural conditions. Detailed geodesic survey was carried out on these three polygons (length 515 m, 265 m, and 521 m respectively; total area – 125000 m2) in July of 2015. It was done with single-frequency geodesic GPS Trimble 5700L1 (base station) and TrimbleR3 (rover). Two DEMs were developed using the results of laser scanning of 2007 and the survey of 2015. Volume deformation for whole polygons and its particular parts (beach and foredune ridge) was made by comparison of the DEMs. In the case of touristic load the effect of deflation is 5-15 times higher than the marine erosion of foredune edge. If not affected by an anthropogenic factor the foredune erosion is caused mainly by the sea, and its impact is 6 times higher than that of the natural deflation.

COMPARATIVE ANALYSIS OF THE INFLUENCE OF NATURAL AND ANTHROPOGENIC FACTORS ON THE VISTULA SPIT FOREDUNE EROSION (THE BALTIC SEA

2017 ◽  
Author(s):  
Evgenii Burnashov ◽  
Evgenii Burnashov ◽  
Konstantin Karmanov ◽  
Konstantin Karmanov
Keyword(s):  
Baltic Sea ◽  
Laser Scanning ◽  
Essential Element ◽  
Base Station ◽  
Beach Erosion ◽  
Single Frequency ◽  
Anthropogenic Factors ◽  
The Baltic Sea ◽  
Volume Deformation ◽  
The Baltic

The study gives quantitative estimation of natural landforms sensitivity of accumulative type coasts exposed to human influence. Foredune is an essential element of a morphological structure of thebarrier spits located at the Baltic Sea sand coasts. The study compares contribution of the beach erosion and deflation (soil drifting) to the foredune degradation on the sea shore of the barrier spit with or without the recreational impact. The analysis is performed for three typical polygons located on the Russian part of the Vistula Spit. Chosen polygons present shore segments with various intensity of tourism: visitors from the village, unregulated camp tourism, and nearly natural conditions. Detailed geodesic survey was carried out on these three polygons (length 515 m, 265 m, and 521 m respectively; total area – 125000 m2) in July of 2015. It was done with single-frequency geodesic GPS Trimble 5700L1 (base station) and TrimbleR3 (rover). Two DEMs were developed using the results of laser scanning of 2007 and the survey of 2015. Volume deformation for whole polygons and its particular parts (beach and foredune ridge) was made by comparison of the DEMs. In the case of touristic load the effect of deflation is 5-15 times higher than the marine erosion of foredune edge. If not affected by an anthropogenic factor the foredune erosion is caused mainly by the sea, and its impact is 6 times higher than that of the natural deflation.

scholarly journals Head-on collision between capillary–gravity solitary waves

2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
Marin Marin ◽  
M. M. Bhatti
Keyword(s):  
Surface Tension ◽  
Solitary Waves ◽  
Water Waves ◽  
Free Parameter ◽  
Order Approximation ◽  
Third Order ◽  
Boussinesq Model ◽  
Run Up ◽  
Physical Features ◽  
Third Order Approximation

AbstractThe present study deals with the head-on collision process between capillary–gravity solitary waves in a finite channel. The present mathematical modeling is based on Nwogu’s Boussinesq model. This model is suitable for both shallow and deep water waves. We have considered the surface tension effects. To examine the asymptotic behavior, we employed the Poincaré–Lighthill–Kuo method. The resulting series solutions are given up to third-order approximation. The physical features are discussed for wave speed, head-on collision profile, maximum run-up, distortion profile, the velocity at the bottom, and phase shift profile, etc. A comparison is also given as a particular case in our study. According to the results, it is noticed that the free parameter and the surface tension tend to decline the solitary-wave profile significantly. However, the maximum run-up amplitude was affected in great measure due to the surface tension and the free parameter.

scholarly journals Focusing of long waves with finite crest over constant depth

2013 ◽  
Vol 469 (2153) ◽  
pp. 20130015 ◽  
Author(s):  
Utku Kânoğlu ◽  
Vasily V. Titov ◽  
Baran Aydın ◽  
Christopher Moore ◽  
Themistoklis S. Stefanakis ◽  
...  
Keyword(s):  
Source Region ◽  
Wave Theory ◽  
Long Waves ◽  
Constant Depth ◽  
Large Wave ◽  
Weakly Nonlinear ◽  
Scaling Relationships ◽  
2011 Japan Tsunami ◽  
Wave Heights ◽  
Run Up

Tsunamis are long waves that evolve substantially, through spatial and temporal spreading from their source region. Here, we introduce a new analytical solution to study the propagation of a finite strip source over constant depth using linear shallow-water wave theory. This solution is not only exact, but also general and allows the use of realistic initial waveforms such as N -waves. We show the existence of focusing points for N -wave-type initial displacements, i.e. points where unexpectedly large wave heights may be observed. We explain the effect of focusing from a strip source analytically, and explore it numerically. We observe focusing points using linear non-dispersive and linear dispersive theories, analytically; and nonlinear non-dispersive and weakly nonlinear weakly dispersive theories, numerically. We discuss geophysical implications of our solutions using the 17 July 1998 Papua New Guinea and the 17 July 2006 Java tsunamis as examples. Our results may also help to explain high run-up values observed during the 11 March 2011 Japan tsunami, which are otherwise not consistent with existing scaling relationships. We conclude that N -waves generated by tectonic displacements feature focusing points, which may significantly amplify run-up beyond what is often assumed from widely used scaling relationships.

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.

A Coupled-Mode Technique for the Run-Up of Non-Breaking Dispersive Waves on Plane Beaches

2006 ◽  
Author(s):  
K. A. Belibassakis ◽  
G. A. Athanassoulis
Keyword(s):  
Shallow Water ◽  
Water Waves ◽  
Wave Equations ◽  
Neumann Boundary ◽  
Breaking Waves ◽  
Numerical Results ◽  
Coupled Mode Theory ◽  
Mode Theory ◽  
Coupled Mode ◽  
Run Up

A coupled-mode model is developed and applied to the transformation and run-up of dispersive water waves on plane beaches. The present work is based on the consistent coupled-mode theory for the propagation of water waves in variable bathymetry regions, developed by Athanassoulis & Belibassakis (1999) and extended to 3D by Belibassakis et al (2001), which is suitably modified to apply to a uniform plane beach. The key feature of the coupled-mode theory is a complete modal-type expansion of the wave potential, containing both propagating and evanescent modes, being able to consistently satisfy the Neumann boundary condition on the sloping bottom. Thus, the present approach extends previous works based on the modified mild-slope equation in conjunction with analytical solution of the linearised shallow water equations, see, e.g., Massel & Pelinovsky (2001). Numerical results concerning non-breaking waves on plane beaches are presented and compared with exact analytical solutions; see, e.g., Wehausen & Laitone (1960, Sec. 18). Also, numerical results are presented concerning the run-up of non-breaking solitary waves on plane beaches and compared with the ones obtained by the solution of the shallow-water wave equations, Synolakis (1987), Li & Raichlen (2002), and experimental data, Synolakis (1987).

scholarly journals Long-term spatial variations in the Baltic Sea wave fields

Ocean Science ◽  
2011 ◽  
Vol 7 (1) ◽  
pp. 141-150 ◽  
Author(s):  
T. Soomere ◽  
A. Räämet
Keyword(s):  
Baltic Sea ◽  
Spatial Variations ◽  
Extreme Wave ◽  
The Baltic Sea ◽  
Wave Fields ◽  
Wave Heights ◽  
The Baltic ◽  
Wave Properties ◽  
Sea Wave

Abstract. This study focuses on spatial patterns in linear trends of numerically reconstructed basic wave properties (average and extreme wave heights, wave periods) in the Baltic Sea under the assumption of no ice cover. Numerical simulations of wave conditions for 1970–2007, using the WAM wave model and adjusted geostrophic winds, revealed extensive spatial variations in long-term changes in both average and extreme wave heights in the Baltic Sea but almost no changes in the basinwide wave activity and wave periods. There has been a statistically significant decrease in the annual mean significant wave height by more than 10% between the islands of Öland and Gotland and in the southward sea area, and a substantial increase to the south-west of Bornholm, near the coast of Latvia, between the Åland Archipelago and the Swedish mainland, and between the Bothnian Sea and the Bothnian Bay. Variations in extreme wave heights (defined as the threshold for 1% of the highest waves each year) show similar patterns of changes. In several areas the trends in average and extreme wave heights are different. Such a complicated pattern of changes indicates that (i) different regions of the Baltic Sea basin have experienced widespread but essentially different changes in wind properties and (ii) many seemingly controversial trends and variations established in wave properties at different sites in the recent past may reflect the natural spatial variability in the Baltic Sea wave fields.

Experimental Investigation of Combustion Dynamics in a Turbulent Syngas Combustor

2017 ◽  
Author(s):  
Nikhil Ashokbhai Baraiya ◽  
Baladandayuthapani Nagarajan ◽  
Satynarayanan R. Chakravarthy
Keyword(s):  
High Speed ◽  
Equivalence Ratio ◽  
Bluff Body ◽  
Dynamic Pressure ◽  
Fuel Mixture ◽  
High Amplitude ◽  
Acoustic Oscillations ◽  
Combustion Dynamics ◽  
Dynamic Pressure Measurement ◽  
Body Location

In the present work, the proportion of carbon monoxide to hydrogen is widely varied to simulate different compositions of synthesis gas and the potential of the fuel mixture to excite combustion oscillations in a laboratory-scale turbulent bluff body combustor is investigated. The effect of parameters such as the bluff body location and equivalence ratio on the self-excited acoustic oscillations of the combustor is studied. The flame oscillations are mapped by means of simultaneous high-speed CH* and OH* chemiluminescence imaging along with dynamic pressure measurement. Mode shifts are observed as the bluff body location or the air flow Reynolds number/overall equivalence ratio are varied for different fuel compositions. It is observed that the fuel mixtures that are hydrogen-rich excite high amplitude pressure oscillations as compared to other fuel composition cases. Higher H2 content in the mixture is also capable of exciting significantly higher natural acoustic modes of the combustor so long as CO is present, but not without the latter. The interchangeability factor Wobbe Index is not entirely sufficient to understand the unsteady flame response to the chemical composition.

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