Steady Ship Waves at Low Froude Numbers. Part 2
Abstract
A low-Froude-number asymptotic expansion of the far-field wave- amplitude function defined within the Neumann-Kelvin theoretical framework is presented. This expansion provides a simple analytical approximation defined explicitly in terms of the geometrical characteristics of the ship hull and the disturbance velocity vector. This low-Froude-number analysis shows that the wave resistance and far-field wave pattern of a ship depend strongly on th shape of the hull, notably the presence of flare and the shape of the waterline at the bow and stern. Analysis predicts that the nondimensional wave-resistance coefficient is O(F1sq), where F is the Froude number, for a ship form with a region of flare, O(F to the 4th power) for a ship form that is wall sided everywhere and has either a bow or a stern (or both) that is neither cusped nor round, and O(F to the 6th power) for a wall sided ship form with both bow and stern that are either cusped or round. Analysis also shows that the relative importance of the nonlinear terms in the free-surface boundary condition depends on the shape of the hull. Specifically, the contribution of the nonlinear terms in the free-surface boundary condition to the far-field wave-amplitude function, K, is found to be O(F cubed), irrespectively of the hull form.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1986
- Accession Number
- ADA176805
Entities
People
- Francis Noblesse