Page 116 - Pipelines and Risers

Hydrodynamics around Pipes 89

Extraction of amplitudes and frequencies from the wave spectrum is for each wave
component done according to:

ai = ,/-> (6.16)
where:
wi = i.Aw (6.17)

A 6.1 is the constant difference between successive frequencies.

k. =- (mi >' is the deep water dispersion relation. (6.18)
' g

Figure 6.4 Connection between a frequency domain and a time domain representation of long-crested
waves.

Figure 6.5 2D random long-crested waves.
Further, a random phase angle ai, uniformly distributed between 0 and 2n is assigned to
each wave component. The wave kinematics are thus represented as a sum of linear
components (Figure 6.4).