The in-line and transverse force characteristics of slender surface-piercing cylinders

Wave tank studies have been performed on the influence of proximity and placement orientation relative to wave direction on the forcing experienced by each member of a two cylinder group of nominally identical bottom-pivoted surface-piercing test cylinders under a variety of incident wave conditions. Results for the in-line force characteristics of these influences have been reported via the observed variation in the Morison force coefficients fitted to the measured cylinder tip restraint forces. Variations on cylinder forcing in the transverse direction have also been noted. Results obtained indicate that the influence on wave force characteristics is particularly significant when the relative cylinder spacing is less than approximately two cylinder diameters and that pattern orientation is also important in determining these force characteristics.