Specification of wave data (Input Table)

Data description/conditions:

WAVEREF:

Reference name of wave data set

Unique / Required

HEIGHT:

Wave height

≥ 0.

(Wave height is vertical distance from crest to trough.)

PERIOD:

Wave period

> 0.

DIRECTN:

Direction of wave propagation

≥ 0. and ≤ 360.

(Wave direction is the positive angle in the horizontal global X-Y plane measured from the positive X-axis to the positive Y-axis.)

X-CREST:

X-coordinate of wave crest

Y-CREST:

Y-coordinate of wave crest

None / required

(These coordinates determine the crest position (phase angle) of the wave with respect to the pipeline.)

WAVETYPE:

Wave theory to be applied

Prescribed names: Airy, Stokes 5

[Default: Airy]

(The Airy theory considers only pure sinusoidal waves (1st order), while the Stokes 5 theory is based on a 5th order approach. The Airy theory is suitable in case of small amplitude intermediate and deep water waves, Stokes 5th order theory should be applied for higher deep water waves. However, the Airy theory describes the wave velocities at the sea bed sufficiently accurately in most cases, so for a pipeline on the sea bed Airy can be applied.)

CRESTYPE:

Type of crest of wave

Prescribed names: Long, Short

[Default: Long]

(Long-crested waves are waves with infinite long straight crests perpendicular to the direction of wave propagation. Short-crested waves have sinusoidal crests with a length equal to 1.7 times the wave length in wave propagation direction. Due to dispersion of wave energy the velocities and accelerations, and so the hydro-dynamic forces are smaller compared with a long-crested wave. The short-crested option can only be combined with Airy theory.)

H410121, last changed: 2009-07-22

See also: