GB2446017A

GB2446017A - Wave powered articulated boat

Info

Publication number: GB2446017A
Application number: GB0701527A
Authority: GB
Inventors: James Anthony Smee
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-01-26
Filing date: 2007-01-26
Publication date: 2008-07-30
Also published as: GB0701527D0

Abstract

A wave powered boat is made of a series of linked sections, which move relative to each other when exposed to waves. The power of this relative motion is transferred to systems which propel the boat. Various methods of producing propulsion are described including hydraulic cylinders or bellows (figure 3) for driving a propeller or producing a jet, paddles attached to and moved by the sections (figures 4-5), cable transmission of force (figure 6), direct drive of a generator (figure 7) and driving a rotating, flexible shaft (figure 8).

Description

roductlon. The basic concept for the wave-powered boat is that or a

senes OT unKeu sections, which move relative to each other, the power of this movement or relative motion is transferred to systems, which propel the boat.

Many variations are possible and the simplest is as flg.2. Methods of harnessing the energy are shown in figs. 3 to 11 but the basic principle of sections moving, sliding or hinging relative to each other is the essential part of the generation of propulsion force. Drawings are shown simplified, detailed mechanical arrangements, including streamlining, are necessary in practical applications.

Basic Physics. Consider a floating vessel, for example a 10 ton fishing boat, which is tied to a fixed point on the dockside, and allowed to float up and down with the waves. Then a bending force or moment will be felt at the point where the boat is hinged or fastened to the quayside.

Depending on the displacement of water around the boat a lifting or downward force will push or pull on the boat. This is illustrated in fig. 1. A boat displacing 10 tons may experience a I ton push if the water rises by 10 centimetres on the hull or a downward force if the water falls by 10 centimetres. If this force moves against a load at the hinged point then the force Will move a distance and do work.

Force X Distance = Work Done also Force X Distance I Time = Power Therefore a force of say I tonne (1000 kg) moving 20 centimetres every second can be shown to generate 1000 x 9.81 x 0.2 newton-metres per sec orjouleslsec or watts In this case 19620 watts, 19.62 kW or 26 hp If this power is mechanically, hydraulically or electrically coupled to a propulsion system even at 25% efficiency then the boat will be propelled.

Similar calculations for larger craft with say6 sections of 1,000 tons each indicate that power equivalent to a normal engine is available, especially in seas with say 2 metre high waves.

Auxiliary power will always be needed, as there is no power available in calm seas.

The concept is well proven in static wave energy applications where these principles are being used to generate electricity. A typical unit has been commissioned and a vessel about as big as a train with four carriages is generating 750 kW. This is more than the power required to drive a ship of the same dimensions.

In Use. This concept is intended for use alone or as a booster to the main power for large vessels, an auxiliary engine would be needed for navigation in ports or calm seas. An oil tanker in three or four sections could theoretically generate perhaps 2000 hp in rough seas. Specially designed cargo vessels with sealed sections for containers could be as long as 20 sections of 1600 tons, with a theoretically available power of over 2000 hp. Two or more existing craft could be linked together to produce the same effect. It is also feasible to store the energy in batteries, flywheels for use later or to store heat in units for other applications.

Novelty. The novelty is in the multi-section configuration where the waves move one section relative to the other(s) and that the energy is used to drive the boat in the water not as an alternative energy source. The wave power is harnessed from the rise and fall of the sea level around the boat, which causes a change in the displacement force on the boat. This is quite different from water washing past paddles or floats or turbines. The relative motion described here includes twisting, parallel or side to side motion, which could have a similar result.

Claims

Claims 1. A wave-powered boat using the relative movement of hinged

sections to generate power for propulsion or to assist propulsion.
2. A wave-powered boat similar to claim 1. using the relative movement of hinged sections to generate electrical power used to drive motors used for propulsion with or without electrical energy storage.
3. A wave-powered boat similar to claim 1. using the relative movement of hinged sections to generate hydraulic power which is converted to mechanical power for propulsion.
4. A wave-powered boat similar to claim 1. using the relative movement of hinged sections to generate mechanical power in flywheels and used for propulsion.
5. A wave-powered boat similar to claim 1. using the relative movement of hinged sections to generate mechanical power directly coupled using flexible shafts or cables to the drive used for propulsion.
6. A wave-powered boat similar to claim I using the relative movement of hinged sections to generate power for propulsion directly by using attached paddles or flippers linked to the mechanical movement of the sections.
7. A wave-powered boat similar to claims I to 5 using the relative movement of flexible sections to generate power used for propulsion.