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Wave staticsChang Hsien Kuo

102328

NRCESTReference2

methods3

Significant wave representation 4

Individual wave H1>H2>H3

Brestchneider (1968)H1/3:1/3 (significant wave, )T1/3:Neir et al. (2003)T1/3:T1>T2>T31/3Statistical properties5

Rayleigh distributionRepresentative wave height6

Representative wave height7

Statistical theory for irregular waves8

Rayleigh distribution for wave height9




1/Nth Waves for Rayleigh distribution13



1/Nth Waves for other distributions16

Regular wave17

Irregular wave18

Frequency spectrum of irregular waves19

Fourier transform (Fast FT)

Frequency spectrum of irregular waves20

Brestchneider (1968)

Goda (1988)

Wallops spectrum by Hwung et al . (1981)

Frequency spectra of irregular waves21JONSWAP (1973)

Directional Spectrum of sea waves22

G() : directional distribution of energy spectrumS(f) : energy (power) spectrumDirectional Spectra of sea waves23

Mitsuyasu (1975)

Smax: Spreading parameterDirectional Spectra of sea waves24

Smax=20

Relationship between spectra and wave height25

Zeroth moment of spectrum

Relationship between spectra and wave height26

Relationship between spectra and wave period27

Zeroth and second moments of spectrum

Spectra of sea waves-Example I28

Example I29

Directional spectrumExample-I30

sample average of sixteen directional spectradirectional spectra of in-site buoy measurementsExample-I31

directional spreading function

Power spectrumExample-II32

Example-II33

Example-II34