Environmental Engineering Reference
In-Depth Information
DID YOU KNOW?
Hydrokinetic energy (KE) is the energy possessed by a body of water because
of its motion (KE = 1.2 mv 2 ). Hydrostatic (potential) energy (PE) is the energy
possessed by a body because of its position or location at an elevation or height
above a reference or datum (PE = mgh ).
In some designs, the reactor is actually inside the displacer, while in others it is an
external body. Internal reactors are not subject to wave forces, but external reactors
may experience loads that cause them to move in ways similar to a displacer; thus,
some devices do not have dedicated reactors at all but rather a system of displacers
whose relative motion creates a reaction system (INL, 2005). The three types of
well-known wave energy conversion devices are point absorbers, terminators, and
attenuators (see Figure 7.3):
A point absorber is a floating structure that absorbs energy in all directions
by virtue of its movements at or near the water surface (see Fig u r e 7.4 ). It
may be designed so as to resonate—that is, move with larger amplitudes
than the waves themselves. This feature is useful to maximize the amount
of power that is available for capture. The power take-off system may take a
number of forms, depending on the figuration of displacers/reactors.
A terminator is also a floating structure that moves at or near the water
surface, but it absorbs energy in only a single direction (see Fig u r e 7. 5 ). The
device extends in the direction normal to the predominant wave direction,
so that as waves arrive the device restrains them. Again, resonance may be
employed and the power take-off system may take a variety of forms.
Wave
Direction
Terminators
Attenuators
Point absorbers
FIGURE 7.3 Wave energy converters. (Adapted from Tovey, N.K., ENV-2E02 Energy
Resources 2004-2005 Lecture , University of East Anglia, Norwich, U.K., 2005.)
 
Search WWH ::




Custom Search