Accession Number : ADA130516

Title :   Vertical Plane Motions of SWATH (Small Waterplane Area Twin Hull) Ships in Regular Waves,

Corporate Author : DAVID W TAYLOR NAVAL SHIP RESEARCH AND DEVELOPMENT CENTER BETHESDA MD SHIP PERFORMANCE DEPT

Personal Author(s) : McCreight,K K ; Stahl,Ralph

PDF Url : ADA130516

Report Date : Jun 1983

Pagination or Media Count : 111

Abstract : The vertical plane motions of SWATH ships are theoretically modeled. Strip theory is used to evaluate hydrodynamic forces. Contributions due to body lift, cross flow drag, and fin lift dominate the damping coefficients. Consequently, their accurate modeling is vital to the accuracy of motion predictions. Semiempirical methods developed for evaluating these components are described. Data for oscillating two-dimensional cylinders, flat plates, and pairs of fins as well as semiempirical expressions for submarine hydrodynamic coefficients have been utilized in this development. Correlation between predicted and experimental results are presented for hydrodynamic coefficients, exciting force and moment, and responses to regular waves. The expressions developed result in correlation which is good and which is notably better than results reported previously.

Descriptors :   *Ship motion, *Mathematical models, Hydrodynamics, Coefficients, Damping, Ship hulls, Struts, Water waves, Moments, Vertical orientation, Equations of motion, Lift, Drag, Cross flow, Hydrodynamic control surfaces, Fins, Oscillation, Potential flow, Viscosity, Pitch(Motion), Heaving, Mathematical prediction, Seaworthiness

Subject Categories : Numerical Mathematics
      Marine Engineering
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE