tmapsd#
[f, Syy, Hm0, fp, Tp, Tm01, Tm02, PHI] = tmapsd(U10, F, h, fp, fs, N, CalSpectralSP, transfCalcMethod, kCalcMethod, dispout)
Description#
Calculate TMA spectrum (power spectral density), (Bouws et al. 1985)
Inputs#
- U10=10;
Wind velocity at 10 meter above surface level in (m/s)
- F=10000;
Wind fetch length in (m)
- h=5;
Mean water depth in (m)
- fp=0.33;
- Peak wave frequency (fp=1/Tp) in (Hz)If CalSpectralSP=’yes’; then fp is calculated from U10 and F
- fs=2;
Sampling frequency that data collected at in (Hz)
- N=256;
Total number of points between 0 and fs that spectrum reports at is (N+1)
- CalSpectralSP=’yes’;
Define to calculate spectral shape parameters or not (‘yes’: calculate, ‘no’: use given parameters by user)
- transfCalcMethod=’approx’;
- Transformation function from JONSWAP into TMA calculation method‘approx’: approximated method, ‘tucker’: Tucker (1994), ‘kitaigordskii’: Kitaigordskii et al. (1975)
- kCalcMethod=’beji’;
- Wave number calculation method‘hunt’: Hunt (1979), ‘beji’: Beji (2013), ‘vatankhah’: Vatankhah and Aghashariatmadari (2013)‘goda’: Goda (2010), ‘exact’: calculate exact value
- dispout=’no’;
Define to display outputs or not (‘yes’: display, ‘no’: not display)
Outputs#
- f
Frequency (Hz)
- Syy
Wave Energy Power Spectrum (m^2/Hz)
- Hm0
Zero-Moment Wave Height (m)
- fp
Peak wave frequency (Hz)
- Tp
Peak wave period (second)
- Tm01
Wave Period from m01 (second), Mean Wave Period
- Tm02
Wave Period from m02 (second), Mean Zero Crossing Period
- PHI
Transformation function from JONSWAP into TMA
Examples#
[f,Syy,Hm0,fp,Tp,Tm01,Tm02,PHI]=tmapsd(10,10000,5,0.33,2,256,'yes','approx','beji','yes');
References#
Beji, S. (2013). Improved explicit approximation of linear dispersion relationship for gravity waves. Coastal Engineering, 73, 11-12.
Bouws, E.; Günther, H.; Rosenthal, W., and Vincent, C.L., (1985). Similarity of the wind wave spectrum in finite depth water: 1. Spectral form. Journal of Geophysical Research: Oceans, 90(C1), 975-986.
Goda, Y. (2010). Random seas and design of maritime structures. World scientific.
Hunt, J. N. (1979). Direct solution of wave dispersion equation. Journal of the Waterway Port Coastal and Ocean Division, 105(4), 457-459.
Kitaigordskii, S. A., Krasitskii, V. P., & Zaslavskii, M. M. (1975). On Phillips’ theory of equilibrium range in the spectra of wind-generated gravity waves. Journal of Physical Oceanography, 5(3), 410-420.
Vatankhah, A. R., & Aghashariatmadari, Z. (2013). Improved explicit approximation of linear dispersion relationship for gravity waves: A discussion. Coastal engineering, 78, 21-22.
Tucker, M. J. (1994). Nearshore waveheight during storms. Coastal Engineering, 24(1-2), 111-136.