MS Thesis R. Hager - Hawaii National Marine Renewable Energy ...

Figure 3. 2 Individual waves travel at a phase velocity, as wave groups travel at group velocity (Newman, 1977)The wave slope and wave dispersion dictate the applicability of linear wave theory. The waveslope is the wave height to wavelength ratio; it is assumed to be extremely small in linearwave theory. Linear wave theory is typically only applicable in deep and intermediate waterdepths, where deep water is defined asdepthwavelength 0.5, and intermediate water bydepth0.05 0.5wavelength. The limitation of linear wave theory with respect to the wave slope andwave dispersion is presented in Figure 3.3.This thesis terms the ratio of the characteristic body length to the wavelength as thediffraction parameter. Diffraction theory is applicable when the structure length spans asignificant portion of the wavelength, and thus incoming waves undergo scattering. The goalof this study is to detect geometric effect on wave power absorption, and thus diffractiontheory is applied.42