Relative Bow Motion and Frequency of Slamming of SWATH Cross-Structure
Abstract
A study was made of methods for improving the means of estimating the expected number of wave impacts per unit time of the SWATH ship cross-structure. Two avenues were explored: (1) Improvement of relative motion estimates by adding the components of ship-generated wave and diffracted wave to the incident wave in describing the free surface; and, (2) including a limiting impact angle in the criteria defining the occurrence of a slam in the formulation of the level-crossing definition from which the expected number of impacts is derived. The results of this study show that including the ship-generated wave and diffracted wave does not improve the correlation of the computed relative motion with results obtained from experiments. Imposing a limiting impact angle on the definition of cross-structure slamming, as expected, reduces the estimated frequency of slamming. Additional model experiments are recommended to obtain a more definitive estimate of threshold velocity and limiting impact angle for estimating SWATH cross-structure slamming frequencies of occurrence.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1986
- Accession Number
- ADA166893
Entities
People
- David W Taylor
- Ernest E. Zarnick
- Young S. Hong