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

concavity from concave down to concave up at Body 21. The maximum power absorptionefficiency decreases more rapidly with the convex bodies than the concave. However, notefrom Table 4.3 and Figure 4.29 that the maximum power absorption efficiency isconsistently higher for convex bodies compared to concave. At a period of 0.6 sec themaximum power absorption efficiency fall from 86.30% to 70.77% from the most convexbody to the most concave body. Comparatively, at a period of 1.0 sec the maximum powerabsorption efficiency falls from 53.04% to 49.70% from the most convex body to the mostconcave body.The wave no longer detects the shape of the body at a period of 1.0 sec (1 Hz) because thewavelengths are much greater than the body length, as seen in Figure 4.30. As previouslystated for the wave to detect the body’s shape the body length must span a significantportion of the wavelength. Note at a period of 1.0 sec the body spans 11% of thewavelength.Figures 4.31 and 4.32 present the normalized heave forces versus the normalized frequenciesfor Bodies 1, 21, and 39 as the body is impinged at 0° and 180°, respectively. Recall the forceis normalized byX igWB (H /2), and the frequency is normalized by 2B2g. Note fromFigures 4.30 and 4.31 that the concave bodies consistently experience greater force than theconvex bodies. Additionally, the curved faces of the bodies (0°) experience greater forcesthan the flat face of the bodies (180°). The percentage difference between the normalizedforce as the wave impinges body 1 at 0° and 180° at T = 0.6 sec is 85.91%. Comparatively ,76