Mean Wave Drift Forces and Moments

Mean wave drift forces and moments are determined in the program for a given wave condition by integrating the regular drift coefficients over a range of frequencies as discussed in Ref.[]. The forces and moments which depend on the wave spectrum , significant wave height and average wave period T are given by:

The frequencies , at which the regular drift coefficients are applied are given by equation (75). The significant wave height and average wave period are introduced through the wave spectrum which can be either ITTC or JONSWAP as defined in Ref.[]. These spectra are given by:

• ITTC

  (77)

where

• JONSWAP

  (78)

where

and