The hydrodynamic coefficients for swaying, heaving and rolling cylinders in a free surface¹

Article type: Research Article

Authors: Vugts, J.H.

Affiliations: Shipbuilding Laboratory, Delft Technological University

Note: [1] Report 112 S Netherlands Ship Research Centre TNO.

Abstract: For various cross-sections the hydrodynamic coefficients of two-dimensional cylinders are determined by forced oscillation tests and by theoretical computations. The purpose of this study is to check the theoretical basis of the computations for all three possible modes of motion and to establish the influence of section shape in this respect. The results show good agreement for heaving and for swaying, while there is a fair correspondence for rolling. Apart from deviations due to experimental inaccuracies appreciable differences between theory and experiment only exist for the coefficients of those terms which dissipate energy in sway and roll. There viscous effects are distinctly present, especially for sharply edged sections in roll. The wave exciting terms in the two-dimensional case are measured and compared to calculations as well. So a complete set of hydrodynamic quantities for the coupled motions of cylinders in beam waves is presented.

DOI: 10.3233/ISP-1968-1516702

Journal: International Shipbuilding Progress, vol. 15, no. 167, pp. 251-276, 1968