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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.
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 ...
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.
A 1682 demonstration of Huygens gunpowder engine, where a dram of gunpowder creates enough vacuum to lift 8 boys into the air. Huygens, however, became interested in the mechanical power of the vacuum, and the possibility of using gunpowder to produce one. In 1678 he outlined a gunpowder engine consisting of a vertical tube containing a piston ...
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.
In both cases the lift vector is the same (as seen by an observer on the ground), but in the latter the vertical axis of the aircraft points downwards, making the lift vector's sign negative. In turning flight the load factor is normally greater than +1. For example, in a turn with a 60° angle of bank the load factor is +2. Again, if the same ...
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The aerodynamic force is the resultant vector from adding the lift vector, perpendicular to the flow direction, and the drag vector, parallel to the flow direction. Forces on an aerofoil . In fluid mechanics , an aerodynamic force is a force exerted on a body by the air (or other gas ) in which the body is immersed, and is due to the relative ...