
654 Principles of Sustainable Energy Systems
© 2008 Taylor & Francis Group, LLC
To calculate the power that can be extracted from deepwater waves, we shall simplify
the rigorous mathematical treatment. It shows that for a surface wave of amplitude a and
wave number k, the radius r of particle motion below the surface is
kz
(11.4)
where
k = 2π/λ
z is the distance below the surface, as shown in Figure 11.24
The vertical displacement from the average position as a function of time t is
∆
kz
==
(11.5)
and the horizontal velocity component,
is
x
kz
==ωω
(11.6)
Then, P
1
, the power in the wave at x per unit width of wave-f ...