Page 113 - Pipelines and Risers
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86 Chapter 6
Figure 6.1 shows the parameters that are used when defining a 2D regular long-crested wave
propagating in the positive x-direction.
X
zb I
Figure 6.1 Parameters used when defining 2D regular waves.
where:
L Wave length.
H Wave height.
d zs - zb = still water depth.
a Wave amplitude cH/2).
T Wave period.
g Acceleration due to gravity.
t Time.
a Phase angle (radians).
x Direction of wave propagation
2n
Wave frequency, o = -
T
2n
Wave number, k = -
L
The dispersion relation expresses the relation between the wave period and wavelength and is
given by:
wz
- tanh(kd) (6.3)
=
gk
6.3.2 2D Regular Long-Crested Waves
The 2D regular long-crested waves Pigure 6.2) are defined by their wave amplitude and
frequency, giving the following expressions for the wave kinematics:
