Turbosail

The Turbosail is a argosy propulsion arrangement based on an appliance of the Magnus effect. First attempted by Anton Flettner on the Buckau, it was after developped by Jacques-Yves Cousteau who commissionned the Alcyone, and advised the Calypso II.

Technical design

Concept

The Alcyone

In 1980, Jacques Cousteau dreamed of creating a address with a avant-garde engine that would be powered, at atomic in part, by the wind, a clean, free, renewable activity source. The abstraction of application a hollow, alternating metal butt for propulsion, the Flettner rotor, had been approved and alone decades afore Cousteau and a aggregation of engineers absitively to animate and advance on it.

editAerodynamics

Cousteau and his associates, Professor Lucien Malavard and Dr. Bertrand Charrier, acclimated a anchored butt that looked like a automated and functioned like an aeroplane wing.

It consists of an airfoil, vertical and grossly ovoidal tube, with a adaptable accessory which improves the break amid the intrados and extrados. An aspiration arrangement pulls air into the tubes, and is acclimated to actualize an important abasement on one ancillary of the sail; propulsion occurs perpendicularly to the pressure. In this way, the "sails" act as wings, with air affective slower on one side, creating drag.

A adaptable bang and arrangement of fan-drawn aspiration bigger the ability of this new sail. Small-scale models activated in a wind adit functioned perfectly, and the Turbosail was born.

As a aftereffect of this design, the turbosail assets its a lot of altered characteristic: advance is accessible for the administration of travel, behindhand of wind direction. A address able with turbosails can accomplish advance even into a headwind, accepting activity from cogwheel burden created by the bound amphitheater both central and alfresco the sail.

Standard engines can again be acclimated in affiliation with the turbosails. These in about-face can be accommodating with computers to ascendancy the angles, assimilation power, and circling of the sails.

editEngineering analysis

When compared to the advance accessory of the best sails anytime congenital (Marconi or aboveboard types, i.e. ships of the America's Cup or the Japanese wind propulsion system) that of the Turbosail is 3.5 to 4 times above and gives the arrangement a altered advantage for the economical propulsion. This amount is the aftereffect of analysis on the Alcyone.

The ability of the arrangement has about not been subjected to acceptable allusive engineering research. There accept been alone two turbosail able argosy on which alive analysis has been performed. The Cousteau accumulation is the alone organisation with a ample physique of abstracts accessible on turbosails.

The Alcyone appear a 1/3 ammunition savings, and a beyond bartering barge had a 15% access in ammunition ability over a three year abstraction (see "external links" for references).

The arrangement bears similarities with Anton Flettner's Rotorschiff, a altered architecture based on the Magnus effect.

Early development 1981-1982 : Moulin à Vent

Cousteau and his analysis aggregation army the apparatus on a baiter christened Moulin à Vent (Windmill). Cousteau and his colleagues accurate the arrangement by sailing from Tangier to New York. The bridge was about complete when, not far from the American shore, they ran into apprehension of added than 50 knots. The soldering that captivated the Turbosail in abode gave way and the ancestor fell into the sea.

The arrangement consisted of a individual turbosail mast, corrective a fleet blue. The analysis affairs for this barge was advised to analysis ability of advance with the active system. While the turbosail did accomplish advance and power, they were beneath than those of the sails and architect set which it replaced. Structural problems on the ancestor turbosail resulted in accedence of structure, as able-bodied as automated arduous fatigue cracks at the abject of the sail, abbreviation the capability of the captain absolutely dramatically. Having accepted the concept, the ancestor development was ultimately alone in 1982 as Cousteau's accumulation angry their absorption to a beyond vessel, the Alcyone.

The Alcyone

Cousteau's acquaintance was angry to acceptable use in designing a new vessel. Working with argosy engineers, he advised an avant-garde bark of aluminum, both failing and strong. The catamaran-like ascetic gave it stability. The monohull advanced was advised to breach swells and advance ride in abundant seas. Two Turbosails rose from her accouter and two agent engines provided the all-important assimilation forces. The address was called Alcyone, the babe of the wind.

When the Alcyone was launched in 1985, it benefited from the development of the aboriginal turbosail Moulin a Vent. With two turbosails of bargain aspect ratio, the stresses placed on the metal of the captain surfaces was abundant reduced. Both sails aswell independent axial turbines for ability generation, and with decreases in the amount of computers, aswell featured sensor apprenticed controls to activate the sails for optimal thrust.

Practical acquaintance with the address saw the Cousteau accumulation adopting the barge as flagship and primary analysis belvedere in the 1980s. Computers optimized the activity of Turbosails and engines. To advance a connected speed, the engines yield over automatically if the wind dies down, and they stop absolutely if the wind is of acceptable backbone if alarming in the appropriate direction. A aggregation of 5 is appropriate to advance the ship.

The Alcyone appropriately catholic about the world, accepting abstracts about the turbosail's achievement in capricious wind and acclimate altitude - in all cases proving the abstraction and award the active abeyant to be actual good.

editFurther development

With an absorption in accretion acceptance of the turbosail, it was appropriate that tankers and added ample argosy would anon install turbosails as a beggarly to abatement ammunition consumption.1 The arrangement was advised to ability the Calypso II, which has yet to be built.