Ballonet

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1909 - Berget - ballonet sketch.png
File:FR385120 figs 1-2.png

Patent FR-1907-385120 gives a good example of ballonets used for aerodynamic stability. Édouard Surcouf writes that creating a tail made of separate ballonets reduces risk of damage to the main hull.

A ballonet is an air bag inside the main balloon of an LTA aircraft, enabling the operator to increase the pressure inside the main balloon. As the operator lets out hydrogen to descend, he adds compensatory atmospheric air to the ballonet, thereby maintaining the overall gas pressure and shape of the envelope.[1]

When the balloon, at the beginning of its ascent, is completely inflated with hydrogen, this fabric partition lies against the lower part of the envelope, exactly like a lining. If the balloon rises, the interior gas dilates, because the outer air becomes less dense, and a portion of this gas escapes through automatic valves; the balloon therefore remains fully inflated so long as it rises. If the descent begins, the gas, diminished by the quantity which has escaped during the ascent, no longer suffices to fill the envelope, which would then become flaccid, lose its original shape, and compromise the general equilibrium.
The ballonnet now comes into play; by means of a pump installed in the car, the aeronauts force air into it, until the sum of the new volume it acquires and that of the remaining hydrogen gas, reconstitute the total original volume of the aerostat. In this way the initial conditions of equilibrium are always maintained, in conformity with the calculations of the constructors.[1]

Can also refer to a simple balloon compartment, as in Patent GB-1910-14688. ("the airship is supposed to be 1,000 feet long, 65½ feet in diameter, and divided into 51 balloonets" [does the double "o" make a difference?]).

According to one history, the ballonet was invented by General Jean Baptiste Meusnier, one year after the first Montgolfier ascent, and then revived by Dupuy de Lôme in 1872. The author, Alphonse Berget credits captain Charles Renard with demonstrating the necessity of the ballonet.[2]

Berget mentions de la Vaulx's spherical balloon Le Djinn as a good example of the ballonet in use.[3]

Links

References

  1. ↑ 1.0 1.1 Berget, 1909, Conquest of the Air, pp. 27–28.
  2. ↑ Berget, 1908, Ballons, Dirigeables et Aéroplanes, p. 154.
  3. ↑ Berget, 1908, p. 156.
Enclosing categories LTA, Balloon
Subcategories
Keywords Gas, Ascension, Stability
Start year
End year


This wiki has 82 patents in category "Ballonet". Other techtypes related to Ballonet: Compartments, Gas, Non-rigid, Semi-rigid

Patents in category Ballonet

Publications referring to Ballonet

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