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Hydrogen and helium are the most commonly used lift gases. Although helium is twice as heavy as (diatomic) hydrogen, they are both significantly lighter than air. Thus helium is almost twice as dense as hydrogen. The lifting power in air of hydrogen and helium can be calculated using the theory of buoyancy.
Using the molar volume, the mass of 1 liter of helium (at 1 atmospheres of pressure) is found to be 0.178 g. If helium is used instead of vacuum, the lifting power of every litre is reduced by 0.178 g, so the effective lift is reduced by 13.90625%. A 1-litre volume of hydrogen has a mass of 0.090 g, reducing the effective lift by 7.03125%.
Lifting gas is generally hydrogen, helium or hot air. Hydrogen gives the highest lift 1.1 kg/m 3 (0.069 lb/cu ft) and is inexpensive and easily obtained, but is highly flammable and can detonate if mixed with air. Helium is completely non flammable, but gives lower performance-1.02 kg/m 3 (0.064 lb/cu ft) and is a rare element [33] and much ...
The helium market after World War II was depressed but the reserve was expanded in the 1950s to ensure a supply of liquid helium as a coolant to create oxygen/hydrogen rocket fuel (among other uses) during the Space Race and Cold War. Helium use in the United States in 1965 was more than eight times the peak wartime consumption. [74]
Helium is inert - it does not react with other substances or combust - and its atomic number is 2, making it the second lightest element after hydrogen. Rockets need to achieve specific speeds and ...
Unlike semi-rigid and rigid airships (e.g. Zeppelins), blimps rely on the pressure of their lifting gas (usually helium, rather than flammable hydrogen) and the strength of the envelope to maintain their shape. Blimps are known for their use in advertising, surveillance, and observation due to their maneuverability, slow speeds and steady ...
2013 Tokyo Motor Show - Toyota Fuel Cell Vehicle (FCV) Concept. Photo: Toyota. Internal combustion engine, or ICE, vehicles have been around for a while. Unfortunately, gasoline consumption is ...
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