Aerostat
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| Aerostat |
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| Supported by lighter-than-air gases (aerostats) | ||||||||||||||||||
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| Supported by LTA gases + aerodynamic lift | ||||||||||||||||||
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| Supported by aerodynamic lift (aerodynes) | ||||||||||||||||||
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| Other means of lift | ||||||||||||||||||
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An aerostat is a system that remains aloft primarily through the use of buoyant lighter than air gases to give a vehicle with nearly the same overall density as air. Aerostats include free balloons, airships, and moored balloons. An aerostat's main structural component is its envelope, a lightweight skin containing a lifting gas[1][2] to provide buoyancy, to which other components are attached. One of the most recent deployments of an Aerostat was seen at the opening ceremony of the nineteenth 2010 Commonwealth Games, held in Delhi, India.
Aerostats are so named because they use "aerostatic" lift which is a buoyant force that does not require movement through the surrounding air mass. This contrasts with aerodynes that primarily use aerodynamic lift which requires the movement of at least some part of the aircraft through the surrounding air mass.
The word aerostat was originally French and is derived from the Greek aer (air) + statos (standing).
Terminology
There are two distinct senses for the scope of term aerostat. In the broader sense, the term refers to all systems that remain aloft primarily using aerostatic buoyancy. In the narrower sense, the term is used to refer to the most common type of aerostat which is the moored balloons. This article uses the term in its broader sense. For the narrower sense, see moored balloon.
Types
Moored balloons – Systems that are connected to the surface via one or more tethers. In contrast to the other types of aerostats, moored balloons are non-free flying. Some moored balloons obtain aerodynamic lift, extra stability and considerably greater altitude, via the contours of their envelope or through the use fins or other appropriately shaped surfaces (e.g. Helikites.)
Free balloons - Free-flying buoyant aircraft that move by being carried along by the wind. Types of free balloons include hot air balloons and gas balloons.
Airships - Free-flying buoyant aircraft that can be propelled and steered. Some airships obtain aerodynamic lift via the shape of their envelope or through the addition of fins or other shape. These types of craft are called hybrid airships.
Gallery
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Moored balloons can carry instruments and sensors for long durations that are impractical for other aircraft. -
Free balloons are free moving, unpowered aerostats. The above is a hot air balloon. There are also gas balloons. -
Airships are free flying aerostats that can be propelled and steered.
See also
References
- ^ The Chambers Dictionary. Edinburgh: Chambers Harrap Publishers Ltd. 2000 [1998]. p. 541. ISBN 0-550-14005-X.
the gas-bag of a balloon or airship
{{cite book}}: Check|isbn=value: checksum (help) - ^ The Oxford Illustrated Dictionary. Great Britain: Oxford University Press. 1976 [1975]. p. 281.
fabric enclosing gas-bags of airship