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In a theoretically perfect situation with weightless spheres, a "vacuum balloon" would have 7% more net lifting force than a hydrogen-filled balloon, and 16% more net lifting force than a helium-filled one. However, because the walls of the balloon must remain rigid without imploding, the balloon is impractical to construct with any known material.
A vacuum airship, also known as a vacuum balloon, is a hypothetical airship that is evacuated rather than filled with a lighter-than-air gas such as hydrogen or helium. First proposed by Italian Jesuit priest Francesco Lana de Terzi in 1670, [ 1 ] the vacuum balloon would be the ultimate expression of lifting power per volume displaced.
Corrections are usually made for water vapor and impurity of lifting gas, as well as percentage of inflation of the gas cells at liftoff. [174] Based on specific lift (lifting force per unit volume of gas), the greatest static lift is provided by hydrogen (11.15 N/m 3 or 71 lb f /1000 cu ft) with helium (10.37 N/m 3 or 66 lb f /1000 cu ft) a ...
The reduction of buoyancy by compressing lift gas into pressurized tanks while taking air from the surrounding atmosphere into the vacant space [1] Changing the density of the lifting gas by heating (more buoyancy) or cooling (less buoyancy). The use of vacuum/air buoyancy compensator tanks [2] The use of thrust vectoring using ducted fans or ...
It is unclear how strong a vacuum Guericke's pump was able to achieve, but if it was able to evacuate all of the air from the inside, the hemispheres would have been held together with a force of around 20 kilonewtons (4,500 lbf; 2.2 short tons-force), [7] [8] equivalent to lifting a car or small elephant; a dramatic demonstration of the ...
Bernoulli's principle can be used to calculate the lift force on an airfoil, if the behaviour of the fluid flow in the vicinity of the foil is known. For example, if the air flowing past the top surface of an aircraft wing is moving faster than the air flowing past the bottom surface, then Bernoulli's principle implies that the pressure on the ...
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Helikites range in size from 1 metre (gas volume 0.13 m 3) with a pure helium lift of 30g, up to 14 metres (gas volume 250m 3) able to lift 117 kg. Small Helikites can fly up to altitudes of 1,000 ft, and medium-sized Helikites up to altitudes of 3,000 ft, while large Helikites can achieve 7,000 ft.