Air cavity system (or ACS) is a modern marine
hull
Hull may refer to:
Structures
* Chassis, of an armored fighting vehicle
* Fuselage, of an aircraft
* Hull (botany), the outer covering of seeds
* Hull (watercraft), the body or frame of a ship
* Submarine hull
Mathematics
* Affine hull, in affi ...
design concept based upon capturing air beneath a vessel's hull to reduce drag and increase speed and
fuel efficiency
Fuel efficiency is a form of thermal efficiency, meaning the ratio of effort to result of a process that converts chemical potential energy contained in a carrier (fuel) into kinetic energy or work. Overall fuel efficiency may vary per device, wh ...
.
How it works
The system works by trapping a layer of air bubbles beneath the ship's hull. A dedicated system or an air blower generates air bubbles that pass nonstop under the ship's surface. Along the bottom of the hull, air bubble outlets are located at different sites equally on both the sides of the boat's center.
A layer of bubbles is formed by blowing air at a constant rate, reducing the drag and resistance between the boat and the water.
Operational use
ACS is used on the Russian
Serna- and
Dyugon-class
landing crafts.
See also
*
Froude number
In continuum mechanics, the Froude number (, after William Froude, ) is a dimensionless number defined as the ratio of the flow inertia to the external field (the latter in many applications simply due to gravity). The Froude number is based on t ...
*
Hull (watercraft)
A hull is the watertight body of a ship, boat, or flying boat. The hull may open at the top (such as a dinghy), or it may be fully or partially covered with a deck. Atop the deck may be a deckhouse and other superstructures, such as a funnel, d ...
*
Ship resistance and propulsion
A ship must be designed to move efficiently through the water with a minimum of external force. For thousands of years ship designers and builders of sailing vessels used rules of thumb based on the midship-section area to size the sails for a give ...
References
External links
Air Lubrication system*
Marine propulsion
Boat types
Nautical terminology
Naval architecture
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