Disturbio racial de Tulsa

The montgolfier is a air Means of transport, a Aéronef lighter than the Air also called Aérostat. The concept is simple, one inflates an envelope thanks to hot air. The hot air being lighter than the surrounding air, the balloon thus rises in the airs.

History

The montgolfier was invented by the Frères Montgolfier, Joseph-Michel and Jacques-Etienne, in 1782; the first public experiment took place the June 4th 1783 with Annonay. The September 19th of the same year, a cock, a sheep and a duck made the experiment of the first manned flight with Versailles in front of the king Louis XVI (their balloon is assembled up to 3600 meters), while the October 19th with the Folie Titon, today located Rue of Montreuil at Paris, at the time still borough of Saint-Anthony, the first flight human took place, inhabited by Jean-Baptiste Réveillon, Jean-François Pilâtre de Rozier and Giroud of the Villette.

The November 21st, Jean-François Pilâtre de Rozier and the Marquis d' Arlandes made a second flight, which was commemorated more officially as being the first.

Jean-François Pilâtre de Rozier lost the life some time later when its rozière , hybrid airship made up of a balloon with gas enclosed in an envelope of montgolfier (the heat of the hearth dilates gas and thus avoids the carrying of ballast), took fire and fell.

The first woman to be flown was Elisabeth Thible, the June 4th 1786 with Lyon.

After promising beginnings, the montgolfiers will be supplanted by the charlières , the balloons with gas, of which the first flew away on February 1st 1783 with on its board the inventor even of the balloon the Charles physicist and the Robert brothers. Especially when the Hydrogen, expensive and difficult to prepare, can be replaced by cheap coal gas.

The montgolfiers were delicate to implement with the hearth which it was necessary to supply without putting fire at the balloon, with ashes or a wisp of straw to half consumed.

For the period of decline, the balloons were not equipped with hearth, they were inflated with block on the ground then one released all. The montgolfier rose very quickly for a flight of ten minutes.

In 1972, two inventions were going to start again the montgolfier: a synthetic fiber for the envelope, the Nylon, and a liquefied petroleum gas, the Propane like fuel.

Technology

A modern montgolfier consists of three principal elements: the envelope, the burner and the nacelle.

The envelope

If the Montgolfier brothers had designed their first montgolfiers in skins the amimaux one, today the envelope consists of a fabric of Nylon, treated with a varnish of Polyuréthane to protect it from the ultraviolet rays and to improve the heat capacity, can be smooth or lobed. In both cases, the envelope consists of spindles which are bent together. The shape of the spindles changes according to the type of desired balloon. Beyond 120°C nylon melts.

Volume can go 550 m3, to take along a person alone, with more than 24000 m3 for largest allowing the carrying of forty-five people.

The reduction in temperature per stop of supply hot air is enough to land when there is little wind. The balloons are also equipped with system making it possible to empty them very quickly. There exist three types of systems of deflation, two reversible and final.

  • reversible systems:
    • the circular valve parachute in the upper part of the envelope which is hung before swelling thanks to Velcro S, the pilot can open it, since the nacelle, in the air to release from the hot air in order to put the balloon in descent, the internal pressure makes it possible the valve to be positioned back as soon as the cord of opening is slackened.
    • the fast deflation ; actually a derivative of the first which makes it possible to actuate this same valve and to transform it into a cone allowing to release the air much more quickly. The valve returns in place by actuating another cord. This system is normally used only with the landing by strong wind to avoid with the balloon trailing on the ground.
  • the nonreversible system: it is a stripping panel , more or less large triangle located at the top of the equator of the balloon. The pilot actuates it by means of a cord with the landing. This action causes to open the balloon releasing the hot air thus. It is necessary to position back the system before next takeoff by means of velcro or other straps.

The burner

The Propane in the liquid state is contained in cylindrical bottles in Aluminum (or heavier steel), placed in the nacelle. It goes towards the burner where it vaporizes and is heated in a serpentine. The air-propane mixture is ignited by a continuous night light. The long flame, right under the opening of the envelope, heats the air contained in the balloon, which allows its rise.

The nacelle

They all are practically in Osier. Many of other materials were used, but one always returned to the wicker: most flexible. Except for the manufacture of the French manufacturer “Balloons-Chaize” which uses the Rotin and the manufacturer Britannique “Cameron Balloons” who uses a combination of wicker and cane of Kooboo, Palambang and Tahiti, whose bit is more regular and more resistant. For three passengers, the bottles, a little luggage, traditional dimension is 1 m height, 1,20 m length on 1,10 m of width.

Operation of a montgolfier

The montgolfiers exploit on the one hand the Archimedes' principle and on the other hand the characteristic of gases to have their product (pressure * volume) equal to their product (constant * temperature). This second principle is described by the equation of state of perfect gases.

Under the action of heat, the air dilates. Its density decreases: therefore, with constant pressure, the hot air takes more place for the same weight, or weighs less heavy for same volume as the cold air. One can check this phenomenon, in a calm part, while placing a thermometer on the ground and another with the ceiling. One notes thus that there is a light difference in temperature and than the air with the ceiling is hotter than the air on the ground.

The weight of the unit {balloon + air} depends on the weight of the air contained in the envelope. If one decreases the density of the air contained in the envelope, the weight of the unit decreases and the balloon can “float in the air”, because the weight will become lower than thorough of Archimedes which is a force constant and directed to the top (weight of the moved air).

As the atmospheric pressure decreases with altitude, from approximately 1 hPa by 28 feet (either approximately 8,40m), the mass of the air moved by the balloon decreases. A point of balance will be reached when the weight of the montgolfier is equal to the weight of the air which it moves. Let us note that air escapes from the envelope of the balloon when the atmospheric pressure decreases.

Meetings

See too

Random links:Patrik Shepherd | Georges Kaminis | Kayar | Guy Lechasseur | Circuit breaker (espionage) | Émeute_raciale_de_Tulsa