Improved Boundary Element Methods for Predicting Sectional HydrodynamicCoefficients for Strip Theory Ship Motion Programs

摘要

This technical memorandum presents two improved boundary element methods forpredicting hydrodynamic coefficients of two dimensional sections. The first method is a source distribution method, while the second is a direct method for determining velocity potential. A major objective of these improved methods is to eliminate errors due to irregular frequencies, which currently exist in the close-fit method used by the strip theory program SHIPMO. Both new methods successfully eliminate problems caused by horizontal and vertical line segments with the close-fit method. This technical memorandum also reviews low and high frequency limits of hydrodynamic coefficients.