netsse.tools.envir_cond.JONSWAP_DNV

netsse.tools.envir_cond.JONSWAP_DNV(Tp, Hs, omega, gamma='standard', h=0)

Computes the JONSWAP spectrum corresponding to the input sea state parameters.

The JONSWAP spectrum is formulated as a modification of a Pierson-Moskowitz spectrum for a developing sea state in a fetch limited situation.

Parameters:

• Tp (float) – Peak period [s].

• Hs (float) – Significant wave height [m].

• omega (array_like of shape (Nfreq,)) – Vector of angular frequencies [rad/s].

• gamma ({'standard','DNV',float}, optional) –

  Peak shape parameter [-]. The value can be user-provided as a float. Alternatively, if 'standard' is input, then gamma will take the standard value of 3.3., while a value 'DNV' as input leads to following the procedure 3.5.5.5 described in DNV-RP-C205.

  Tip

  Use gamma = 1 to output a standard Pierson-Moskowitz spectrum.

• h (float, default 0) – Water depth [m]. If h is specified as input argument, then the output JONSWAP spectrum is corrected to account for finite water depth, becoming a standard TMA spectrum as per Bouws et al. (1985).

Returns:

S_J – Standard wave spectrum [m^2.s/rad].

Return type:

array_like of shape (Nfreq,)

References

1. DNV-RP-C205, “Environmental Conditions and Environmental Loads, April 2007.

2. Bouws, E., Gunther, H., Rosenthal, W., & Vincent, C. L. (1985). Similarity of the wind wave spectrum in finite depth water. 1. Spectral form. Journal of Geophysical Research-Oceans, 90(NC1), 975–986. https://doi.org/10.1029/JC090iC01p00975

See also

lin_disprel

A fast and accurate approximation of the linear wave dispersion relationship in finite water depth.

Example

>>> S_J = JONSWAP_DNV(Tp,Hs,omega,gamma='standard',h=0)