Steady ship waves at low Froude numbers, part 2
Abstract
A low-Froude number asymptotic expansion for the far-field wave-amplitude function defined within the Neumann-Kelvin theoretical framework is presented. This asymptotic expansion provides a simple analytical approximation defined explicitly in terms of the geometrical characteristics of the ship hull and the disturbance velocity vector. The low-Froude number analysis presented shows that the wave resistance and the far-field pattern of a ship strongly depend on the shape of the hull, notably the presence of flare and the shape of the waterline at the bow and the stern. In particular, the analysis predicts that the nondimensional wave-resistance coefficient is O(F sup 2), where F is the Froude number, for a ship form with a region of flare, O(F sup 4) for a stopform that is wall sided everywhere O(F sup 4) 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 (sup 6) for a wall-sided ship form with both bow and stern that are either cusped or round.
- Publication:
-
Final Report Naval Ship Research and Development Center
- Pub Date:
- December 1986
- Bibcode:
- 1986nsrd.reptR....N
- Keywords:
-
- Asymptotic Methods;
- Boundary Value Problems;
- Froude Number;
- Nonlinearity;
- Numerical Analysis;
- Ship Hulls;
- Far Fields;
- Prediction Analysis Techniques;
- Velocity;
- Fluid Mechanics and Heat Transfer