Download presentation
Presentation is loading. Please wait.
Published byCharleen May Modified over 9 years ago
1
Efim Pelinovsky, Shallow Rogue Waves: Observations,
laboratory experiments, theories and modelling Efim Pelinovsky, Alexey Slunyaev, Ira Didenkulova, Irina Nikolkina, Anna Sergeeva, Tatiana Talipova Ekaterina Shurgalina Artem Rodin Grant No. FP7 GA Volkswagen Foundation, Germany Department of Nonlinear Geophysical Processes, Institute of Applied Physics, Nizhny Novgorod, RUSSIA Wave Engineering Laboratory, Institute of Cybernetics, Tallinn, Estonia Applied Mathematics Department, State Technical University, Nizhny Novgorod, Russia
2
Shallow water rogue waves in Taiwan
Historical “Rabid-Dog Waves” 50-years Data Base: 140 eyewitness reports from 1949 – 1999 More than 496 people lost their lives and more than 35 crafts were capsized due to nearshore freak waves Taiwan (Chien et al, 2002)
3
Rogue wave in Kalk Bay on 26 August 2005
The wave over 9 m washed two people off the breakwater in Kalk Bay (South Africa). The wave overflows the breakwater.
4
16 October, Trinidad 3 m
5
16 October, Trinidad 3 m
6
16 October, Trinidad 3 m
7
South Korea, May 4, 2008 At least eight people are reported to have
been killed after they were swept away by high waves.
8
the day after a very large storm had passed through.
In October, 1998, thirteen students in the Bamfield Marine Station Fall Program were taken on a field trip to Kirby Point, a wave-beaten peninsula on the southwest corner of Dianna Is. (Barkley Sound, Vancouver Island, British Columbia), to view the large open-ocean swell breaking on the shore the day after a very large storm had passed through. The students split into two groups and sat atop two adjacent rock outcrops, at least 25 meters above sea level After about 45 minutes of wave watching, one student tried to capture the feel of these huge waves thundering onto the shore by taking three pictures in quick succession of what looked to be a nice example of a large wave as it started to break
9
1) A rogue wave starts to break low on the shore
25 m
10
25 m 2) The rogue wave races up the shore
(approximately 2 sec after the first picture) 25 m
11
3) The rogue wave breaks over the students
who were at least 25 meters above sea level (approx. 2 sec after the previous picture)
12
Rogue Waves 2010 February 14, 2010
14
Rogue waves from mass media in 2006-2010
(Nikolkina & Didenkulova, 2011) 78 true events 106 possible
15
Rogue waves in 2006-2010: shallow water
14 of 30 events led to the damage of the vessel, 7 events – to its loss (in deep waters only 5 ships were damaged). These events are also associated with extremely high number of human fatalities (79 persons) and injuries (90 persons). For comparison, the number of human losses in the deep water area is significantly less: 6 fatalities and 27 injuries. In August 2010 the ship carrying 60 people (only 21 rescued) capsized and sank minutes before arriving in harbour. Another large loss of lives (11 fatalities) occurred in this area when a fishing boat “Jaya Baru” was engulfed by 6 m waves in May, 2007.
16
Rogue waves in : coast Totally, during 2006–2010, 39 such events were reported, which caused 46 fatalities and 79 injuries. Usually such waves appear unexpectedly in calm weather conditions and result in the washing the person off to the sea.
17
Rogue waves in 2006-2010: damage
27 6 79 46 5 7 79 90 14
18
Rogue waves in shallow water: possible mechanisms
Wave-current interaction Wave blocking Random caustics Wave-bottom (coast) interaction Focuses “Itself” wave dynamics Nonlinear wave interaction Dispersive focusing Modulational instability Wave-atmosphere interaction Weak dispersion leads to relatively long life- time of individual waves, which makes them more hazardous! The most probable mechanism of rogue wave generation in deep water does not work in shallow water!
19
Tallinn Bay, Baltic Sea, depth 2 m
I.Didenkulova, C.Anderson, Freak waves of different types in the coastal zone of the Baltic Sea. Natural Hazards and Earth System Sciences 2010, 10, I.Didenkulova, Shapes of freak waves In the coastal zone of the Baltic Sea (Tallinn Bay), Boreal Env. Research, 2011, 16, Tallinn Bay, Baltic Sea, depth 2 m
20
Constant Depth, No boundaries
Shallow Water Equations (Hyperbolic System) Constant Depth, No boundaries 1D Problem H – total water depth u – depth averaged velocity g – gravity acceleration
21
Unidirectional Riemann Wave (right)
Velocity of points on wave profile
22
Wave Breaking Wave amplitude/depth
23
“Right” Wave “Left” Wave
24
Weak Amplitude – 0.3 m Depth 1 m
25
Strong Amplitude – 0.9 m Depth – 1m
26
Sign-Variable Wave
27
Sign-Variable Wave Sign-variable wave transforms into unipolar pulse
28
No Variation in Statistics!
Random Non-breaking Riemann Wave No Variation in Statistics! Probability density function W One of them or both are Non-Gaussian
29
Nonlinear Shallow Water Waves on plane beach
(Carrier & Greenspan, 1958)
30
Hodograph Transformation
(Carrier & Greenspan, 1958) Implicit form
31
x(t),r(t) u(t) Explicit solution for the moving shoreline
if an incident wave is given far from the shoreline where it is linear Nonlinear Coordinates and velocity of moving shoreline x(t),r(t) u(t)
32
Nonlinear Coordinates of non-moving shoreline
“Nonlinear” Moving Shoreline Nonlinear Coordinates and velocity of moving shoreline Linear Coordinates and velocity of non-moving shoreline x=0, R(t), U(t) x(t), r(t), u(t)
33
Nonlinear Coordinates of non-moving shoreline
First Result: Linear Theory predicts Maxima for sine wave Nonlinear Coordinates and velocity of moving shoreline Linear Coordinates and velocity of non-moving shoreline x=0, R(t), U(t) x(t), r(t), u(t)
34
Second result: linear theory “predicts” wave breaking
The same as Jacobian Transformation “Linear” Vertical Acceleration = Gravity Acceleration
35
For irregular runup: Linear theory for nonlinear extreme runup characteristics
Nonlinearity does not contribute in Distribution Functions of Heights For narrow-band Gaussian Process – Rayleigh Distribution Significant Wave Height does not change
36
Nonlinear “real” velocity of
the moving shoreline
37
Statistical moments for velocity
“Linear” statistics for “nonlinear” shoreline velocity
38
Nonlinear “real” runup
39
The mean sea level onshore
The mean sea level rises – Set-Up But rmax = Rmax and rmin = Rmin does not change Conclusion: Flooding Time exceeds “Dry” Time
40
Standard deviation for the
sea level onshore Nonlinearity decreases the standard deviation Therefore, nonlinear relation between standard deviation and significant wave height
41
Skewness and kurtosis (> 0)
Shoreline displacement is non Gaussian process, Shoreline velocity (its derivative) is Gaussian
42
Observations of the wave
field onshore
43
Set-up
44
Universal spectra Explanation from kinematics
45
Distribution function
Skewness = 0.2 Distribution function Kurtosis = - 0.6
46
Mean level Skewness and Kurtosis
Denissenko P., Didenkulova I., Pelinovsky E., Pearson J. Influence of the nonlinearity on statistical characteristics of long wave runup. Nonlinear Processes in Geophysics, 2011, 18, Mean level Skewness and Kurtosis Experiments in Hannover large flume will be soon
47
KdV model for shallow water
Inverse scattering method Discrete l - solitons Continuous l – dispersive tail
48
solitons + evolves dispersive train disturbance
Initial disturbance evolves Delta-function (as model of the freak wave) evolves in one soliton and dispersive train Inverted (in x) dispersive train + soliton will evolve in delta-function But delta-function is not weak nonlinear and dispersive wave
49
Maximal soliton - Ursell parameter Number of solitons
Soliton-like disturbance - Ursell parameter Number of solitons Maximal soliton
50
Large Ursell number max = 2 0
Inverting - no generation of freak wave!
51
Small Ursell number 0(freak) > 21 One small soliton
Freak wave is almost linear wave in spite of its large amplitude!
52
h(x) < 0 – solitonless potential
Freak Wave as a deep hole (depression) h(x) < 0 – solitonless potential Only dispersive tail Similar to linear problem No limitations on characteristics of deep holes! Pelinovsky, E., Talipova, T., and Kharif, C. Nonlinear dispersive mechanism of the freak wave formation in shallow water. Physica D, 2000, vol. 147, N. 1-2,
53
Korteweg – de Vries equation
Periodic boundary conditions – cnoidal waves Representation of the solutions through Theta-Function (Matveev, Osborne et al) A.R. Osborne, E. Segre, and G. Boffetta, Soliton basis states in shallow-water ocean surface waves, Phys. Rev. Lett. 67 (1991) A.R. Osborne, Numerical construction of nonlinear wave-train solutions of the periodic Korteweg – de Vries equation, Phys. Rev. E 48 (1993) A.R. Osborne, Behavior of solitons in random-function solutions of the periodic Korteweg – de Vries equation, Phys. Rev. Lett. 71 (1993) A.R. Osborne, Solitons in the periodic Korteweg – de Vries equation, the -function representation, and the analysis of nonlinear, stochastic wave trains, Phys. Review E 52 (1995) N A.R. Osborne, and M. Petti, Laboratory-generated, shallow-water surface waves: analysis using the periodic, inverse scattering transform. Phys. Fluids 6 (1994) A.R. Osborne, M. Serio, L. Bergamasco, and L. Cavaleri, Solitons, cnoidal waves and nonlinear interactions in shallow-water ocean surface waves, Physica D 123 (1998)
54
Korteweg – de Vries equation
Modulated wave field: no Benjamin – Feir instability
104
Demodulation: no freak wave
Recurrence
105
Wind Wave Distribution
106
Gaussian Shape
107
Wave Trajectories, small Ur
108
Wave Trajectories, Ur = 1
110
Moment Calculations skewness kurtosis
111
skewness Relaxation to steady state
112
kurtosis Relaxation to steady state
113
Steady State
114
Ur = 0.2
115
Ur = 1
116
relative spectrum width
117
Crest distribution
118
North Sea (depth 7 m, Hs = 2.5 m, Ts = 8.4 sec)
119
Steady State Initial Spectra
120
Universal curves Pelinovsky, E., and Sergeeva, A. Numerical modeling of the KdV random wave field. European Journal of Mechanics – B/Fluid. 2006, vol. 25, Sergeeva, A., Pelinovsky, E., and Talipova T. Nonlinear Random Wave Field in Shallow Water: Variable Korteweg – de Vries Framework. Natural Hazards and Earth System Science, 2011, vol. 11,
123
Soliton Turbulence V.E. Zakharov, Kinetic equation for solitons, Soviet JETP 60 (1971) A. Salupere, P. Peterson, and J. Engelbrecht, Long-time behaviour of soliton ensembles. Part 1 – Emergence of ensembles, Chaos, Solitons and Fractals, 14 (2002) Salupere, P. Peterson, and J. Engelbrecht, Long-time behaviour of soliton ensembles. Part 2 – Periodical patterns of trajectorism, Chaos, Solitons and Fractals 15 (2003a) Salupere, P. Peterson, and J. Engelbrecht, Long-time behavior of soliton ensembles, Mathematics and Computers in Simulation 62 (2003b) Salupere, G.A. Maugin, J. Engelbrecht, and J. Kalda, On the KdV soliton formation and discrete spectral analysis, Wave Motion 123 (1996) M. Brocchini and R.Gentile. Modelling the runu-up of significant wave groups. Continental Shelf Research, 2001, vol. 21,
124
Statistical Characteristics of Solitons:
No Interaction – Linear Approach Soliton amplitudes and phases are random and statistically independent Phases are uniformly distributed in domain -L/2 < x < L/2
125
Moments of N-Soliton Ensembles
126
Two-soliton Interaction:
elementary act of soliton turbulence «Overtake» «Exchange» Analysis for various ratio of soliton amplitudes
127
Two “first” moments (mean value and dispersion) are constant (KdV invariants)
“Skewness” and “Kurtosis” are reduced when solitons interact
128
Extreme characteristics versus A2/A1
Wave amplitude at collision time Not the same point A1/A2 = 2.8! Skewness difference Kurtosis difference:
129
Numerical Simulation within KdV equation
132
In progress
133
Universal curves Soliton Turbulence, Ur >>1
134
Conclusions: No rogue waves in unidirectional hyperbolic field
2. Rogue Waves in Interacted Riemann Waves 3. Positive skewness growing with Ur in KdV 4. Sign-Variable Kurtosis via Ur in KdV 5. Highest Probabilities for large Ur 6. Universal curves for 3d and 4th moments 7. Soliton turbulence is not Gaussian process with small variations of moments
135
Recent References: 1. Didenkulova I., and Pelinovsky E. Rogue waves in nonlinear hyperbolic systems (shallow-water framework). Nonlinearity, 2011, 24, R1-R18. 2. Slunyaev A., Didenkulova I., Pelinovsky E. Rogue waters. Contemporary Physics. 2011, 52, No. 6, 571 – 590. 3. Pelinovsky, E.N., and Rodin, A.A. Nonlinear deformation of a large- amplitude wave on shallow water. Doklady Physics, 2011, 56, 4. Didenkulova, I., Pelinovsky, E., and Sergeeva, A. Statistical characteristics of long waves nearshore. Coastal Engineering, 2011, 58, 5. Denissenko P., Didenkulova I., Pelinovsky E., Pearson J. Influence of the nonlinearity on statistical characteristics of long wave runup. Nonlinear Processes in Geophysics, 2011, 18, (experiment). 6. Didenkulova I. Shapes of freak waves in the coastal zone of the Baltic Sea (Tallinn Bay). Boreal Environment Research, 2011, 16, 7. Nikolkina I., Didenkulova I. Rogue waves in Natural Hazards and Earth System Sciences, 2011, 11, 8. Sergeeva, A., Pelinovsky, E., and Talipova, T. Nonlinear random wave field in shallow water: variable Korteweg – de Vries framework. Natural Hazards and Earth System Science, 2011, 11, No. 1,
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.