Post on 18-Jan-2021
Waves and Nearshore Circulation
Waves
wave number wave angular frequency
wave steepness relative water depth
Dispersion Relationship
Wave length decreases with decreasing depth
Approximate solution of Fenton & McKee
Go to Wave Calculator
Orbital Motions of Waves
Velocity Profiles
Wave Energy and Energy Flux
Wave Energy Flux
Dynamic Pressure
Look at another bunch of calculators, including wave particle motions
Wave Shoaling
12
Shoaling
Shoaling Coefficient, Ks
Wave Refraction
Where is crest?What are arrows?
Planform
Refraction
Refraction
Wave Diffraction
Calculable: Mathematically; parabolic modeling includes depth changes
Huygen’s Principle
Diffraction Diagram
Wave Breaking
Wave Models
REF/DIF (Kirby & Dalrymple)
RCPWAVE (Ebersole)
CGWave (Panchang)
FUNWAVE (Wei & Kirby)
SWAN (Holthuijsen)
WAVEWATCH III (Tolman)
Breaker Types
Surf Similarity Parameter
Dally, Dean, Dalrymple (1985)
Breaking Waves and Turbulence
Matsunaga (1994), Li and Dalrymple (1998)
Low Frequency Motions: Surf Beat
cross-shore motion only
Linearized long wave equations
cross-differentiate:
For h=m x
Edge Waves: alongshore dependency
Laguerre Polynomials
Edge Waves
Field Observations
Huntley, Guza, Thornton (1981)
Rip Currents, Tang and Dalrymple (1985)
Mean Quantities
Time Average
Depth Average
Depth and Time Average
equal to 0?
Mass Flux
H= 1 m, T= 6 s, h = 5 mE= 1090, C= 6.35, M=171 kg/m-sec
Momentum Flux
caligraphic M, not M (momentum, not mass)
Set-down and Set-up
offshore
inshore
Nearshore Circulation
Numerical models of these equations exist:
SHORECIRC (U Del)
Longshore Current
Longuet-Higgins (1970)
with mixing
Shear Waves
Ozkan-Haller and Kirby, 1999
Oltman-Shay, Howd, Birkemeier, 1989
Boussinesq ModelsSorenson et al. (1998) noticed that wave model
predicted currents
Chen et al. (1999)Haller’s rip current test
Variation in longshore wave height
Rip Currents
Simple Model of Rip Current
sand bar
rip rip incident waves
Dalrymple, 1978
Rip Current Types
Wright & Short,1984
Wright & Short,1984
Palm Beach,AustraliaArgus images
(Ranasinghe et al. 2004)
FUNWAVE: CUSPS
FUNWAVE: Hole
Synchonous Intersecting Wave Trains