Date of Award
Naval Architecture and Marine Engineering
Vincent Xiaochuan Yu
This thesis analyzes the effects of the angle of heel and beam-to-draft ratio on the sectional added mass of primitive cross-sectional shapes in regular harmonic waves in the frequency domain using 2-D boundary element method for uncoupled heave, sway, and roll motion. This 2-D boundary element method uses the patch method developed by Söding (1993b)  to compute the added mass of asymmetric geometry. The angles of heel used varied from 0 to 90 degrees in 5-degree intervals, while the beam-to-draft ratios varied from B/T = 0.5 to B/T = 3.0 in half increments. Triangles, rectangles, and rectangles with rounded bilges (rounded corners at the baseline), were the cross-sections analyzed, with two different bilge radii: 0.5 feet and 2.0 feet. It was found that for all the shape types, certain angles of heel can result in significant negative added mass, for roll and heave. It was outside the scope of this thesis to determine whether this affected vessel response, but it was concluded that the presence of this negative added mass meant a reduction in inertial forces on the cross-sections. In addition, it was found that angle of heel and beam-to-draft ratio cause the added mass curves to significantly change in magnitude and shape. Generally increasing B/T ratio causes the added mass to increase in magnitude and for the curves to flatten, especially for heave. Changing the heel angle influences the location of the peak added mass, and corresponding encounter frequency, generally causing it to move to lower frequencies for heave and roll. However, for sway motion the peak frequency generally gained in value with the angle of heel.
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Bacon, Adam N., "Investigation of Added Mass of Heeled 2-D Sections in a Seaway using the Patch Method in Heave, Roll, and Sway Motions" (2021). University of New Orleans Theses and Dissertations. 2940.
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