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Thermal Airship
A thermal airship is an airship that generates buoyancy by heating air in a large chamber or envelope. The lower density of interior hot air compared to cool ambient air causes an upward force on the envelope. This is very similar to a hot air balloon, with the notable exception that an airship has a powered means of propulsion, whilst a hot air balloon relies on winds for navigation. An airship that uses steam would also qualify as a thermal airship. Other types of airships use a gas that is lighter than air at ambient temperature, such as helium, as a lifting gas. Some airship designs that use a lighter-than-air lifting gas heat a portion of the gas, which is usually maintained in enclosed cells to gain additional lift. Heating the lifting gas causes expansion of the gas in order to further lower the density of the lifting gas, which results in greater lift. Advantages and disadvantages Thermal airships have the advantage of being much less expensive than helium-based airshi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Airship
An airship, dirigible balloon or dirigible is a type of aerostat (lighter-than-air) aircraft that can navigate through the air flying powered aircraft, under its own power. Aerostats use buoyancy from a lifting gas that is less dense than the surrounding air to achieve the lift (physics), lift needed to stay airborne. In early dirigibles, the lifting gas used was hydrogen gas, hydrogen, due to its high lifting capacity and ready availability, but the inherent flammability led to several fatal accidents that rendered hydrogen airships obsolete. The alternative lifting gas, helium gas is not flammable, but is rare and relatively expensive. Significant amounts were first discovered in the United States and for a while helium was only available for airship usage in North America. Most airships built since the 1960s have used helium, though some have used thermal airship, hot air. The envelope of an airship may form the gasbag, or it may contain a number of gas-filled cells. An air ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zeppelin
A Zeppelin is a type of rigid airship named after the German inventor Ferdinand von Zeppelin () who pioneered rigid airship development at the beginning of the 20th century. Zeppelin's notions were first formulated in 1874Eckener 1938, pp. 155–157. and developed in detail in 1893.Dooley 2004, p. A.187. They were patented in German Empire, Germany in 1895 and in the United States in 1899. After the outstanding success of the Zeppelin design, the word ''zeppelin'' came to be commonly used to refer to all forms of rigid airships. Zeppelins were first flown commercially in 1910 by Deutsche Luftschiffahrts-AG (DELAG), the world's first airline in revenue service. By mid-1914, DELAG had carried over 10,000 fare-paying passengers on over 1,500 flights. During World War I, the German military made extensive use of Zeppelins German strategic bombing during World War I, as bombers and aerial reconnaissance in World War I, as scouts. Numerous bombing raids on United Kingdom of Great Brita ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Propane
Propane () is a three-carbon chain alkane with the molecular formula . It is a gas at standard temperature and pressure, but becomes liquid when compressed for transportation and storage. A by-product of natural gas processing and petroleum refining, it is often a constituent of liquefied petroleum gas (LPG), which is commonly used as a fuel in domestic and industrial applications and in low-emissions public transportation; other constituents of LPG may include propene, propylene, butane, butene, butylene, butadiene, and isobutylene. Discovered in 1857 by the French chemist Marcellin Berthelot, it became commercially available in the US by 1911. Propane has lower volumetric energy density than gasoline or coal, but has higher gravimetric energy density than them and burns more cleanly. Propane gas has become a popular choice for barbecues and portable stoves because its low −42 °C boiling point makes it vaporise inside pressurised liquid containers (it exists in two pha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vectored Thrust
Thrust vectoring, also known as thrust vector control (TVC), is the ability of an aircraft, rocket or other vehicle to manipulate the direction of the thrust from its engine(s) or motor(s) to control the attitude or angular velocity of the vehicle. In rocketry and ballistic missiles that fly outside the atmosphere, aerodynamic control surfaces are ineffective, so thrust vectoring is the primary means of attitude control. Exhaust vanes and gimbaled engines were used in the 1930s by Robert Goddard. For aircraft, the method was originally envisaged to provide upward vertical thrust as a means to give aircraft vertical (VTOL) or short (STOL) takeoff and landing ability. Subsequently, it was realized that using vectored thrust in combat situations enabled aircraft to perform various maneuvers not available to conventional-engined planes. To perform turns, aircraft that use no thrust vectoring must rely on aerodynamic control surfaces only, such as ailerons or elevator; aircraft w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aluminium
Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has a great affinity towards oxygen, passivation (chemistry), forming a protective layer of aluminium oxide, oxide on the surface when exposed to air. It visually resembles silver, both in its color and in its great ability to reflect light. It is soft, magnetism, nonmagnetic, and ductility, ductile. It has one stable isotope, 27Al, which is highly abundant, making aluminium the abundance of the chemical elements, 12th-most abundant element in the universe. The radioactive decay, radioactivity of aluminium-26, 26Al leads to it being used in radiometric dating. Chemically, aluminium is a post-transition metal in the boron group; as is common for the group, aluminium forms compounds primarily in the +3 oxidation state. The aluminium cation Al3+ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tensile Membrane Structure
Tension is the pulling or stretching force transmitted axially along an object such as a string, rope, chain, rod, truss member, or other object, so as to stretch or pull apart the object. In terms of force, it is the opposite of ''compression''. Tension might also be described as the action-reaction pair of forces acting at each end of an object. At the atomic level, when atoms or molecules are pulled apart from each other and gain potential energy with a restoring force still existing, the restoring force might create what is also called tension. Each end of a string or rod under such tension could pull on the object it is attached to, in order to restore the string/rod to its relaxed length. Tension (as a transmitted force, as an action-reaction pair of forces, or as a restoring force) is measured in newtons in the International System of Units (or pounds-force in Imperial units). The ends of a string or other object transmitting tension will exert forces on the objects to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cameron D-96
The Cameron D-96 was the first hot air airship, a powered, steerable lighter-than-air craft carrying two or three crew marrying the elongated envelope of an airship with the externally localized heat source of a modern hot air balloon. It was designed and built in the UK and first flown in 1973. Design and development Cameron Balloons had been producing hot air balloons for five years when they designed the world's first hot air airship or thermal airship. This, the D-96, has much in common with the balloons, being a non-rigid airship, covered in a nylon fabric and with a propane burner to feed hot air into the envelope from a gondola suspended below it. However, it has the elongated body shape of conventional helium and hydrogen filled airships, airscrew propulsion and stabilizing tailfins. With a length to maximum diameter ratio of only about 2.5, the envelope is fatter than that of many airships. The D-96 is powered a 1.6 L Volkswagen engine, modified to run on propane ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Airspeed
In aviation, airspeed is the speed of an aircraft relative to the air it is flying through (which itself is usually moving relative to the ground due to wind). In contrast, the ground speed is the speed of an aircraft with respect to the surface of the Earth (whether over land or presumed-stationary water). It is difficult to measure the exact airspeed of the aircraft (true airspeed), but other measures of airspeed, such as indicated airspeed and Mach number give useful information about the capabilities and limitations of airplane performance. The common measures of airspeed are: * Indicated airspeed (IAS), what is read on an airspeed gauge connected to a pitot-static system. * Calibrated airspeed (CAS), indicated airspeed adjusted for pitot system position and installation error. * True airspeed (TAS) is the actual speed the airplane is moving through the air. When combined with aircraft direction, wind speed and direction, it can be used to calculate ground speed and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
