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Ballonet Analogue
A ballonet is an air bag inside the outer envelope of an airship which, when inflated, reduces the volume available for the lifting gas, making it more dense. Because air is also denser than the lifting gas, inflating the ballonet reduces the overall lift, while deflating it increases lift. In this way, the ballonet can be used to adjust the lift as required. Ballonets may typically be used in non-rigid or semi-rigid airships, commonly with multiple ballonets located both fore and aft to maintain balance and to control the pitch of the airship. The image illustrates the principle of a balloon within a balloon. The outer balloon represents the airship's outer envelope or gasbag, while the red inner balloon represents the ballonet. In an airship the ballonet would be much smaller relative to the size of the gasbag; for example, in the French airship Lebaudy Patrie the volume of the ballonet was approximately one-fifth that of the envelope. History The ballonet was first descr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ballonet Analogue
A ballonet is an air bag inside the outer envelope of an airship which, when inflated, reduces the volume available for the lifting gas, making it more dense. Because air is also denser than the lifting gas, inflating the ballonet reduces the overall lift, while deflating it increases lift. In this way, the ballonet can be used to adjust the lift as required. Ballonets may typically be used in non-rigid or semi-rigid airships, commonly with multiple ballonets located both fore and aft to maintain balance and to control the pitch of the airship. The image illustrates the principle of a balloon within a balloon. The outer balloon represents the airship's outer envelope or gasbag, while the red inner balloon represents the ballonet. In an airship the ballonet would be much smaller relative to the size of the gasbag; for example, in the French airship Lebaudy Patrie the volume of the ballonet was approximately one-fifth that of the envelope. History The ballonet was first descr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jacques Charles
Jacques Alexandre César Charles (November 12, 1746 – April 7, 1823) was a French inventor, scientist, mathematician, and balloonist. Charles wrote almost nothing about mathematics, and most of what has been credited to him was due to mistaking him with another Jacques Charles, also a member of the Paris Academy of Sciences, entering on May 12, 1785. He was sometimes called Charles the Geometer. Charles and the Robert brothers launched the world's first unmanned hydrogen-filled gas balloon in August 1783; then in December 1783, Charles and his co-pilot Nicolas-Louis Robert ascended to a height of about 1,800 feet (550 m) in a manned gas balloon. Their pioneering use of hydrogen for lift led to this type of balloon being named a ''Charlière'' (as opposed to a Montgolfière which used hot air). Charles's law, describing how gases tend to expand when heated, was formulated by Joseph Louis Gay-Lussac in 1802, but he credited it to unpublished work by Jacques Charles. Charles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linear Actuator
A linear actuator is an actuator that creates motion in a straight line, in contrast to the circular motion of a conventional electric motor. Linear actuators are used in machine tools and industrial machinery, in computer Peripheral, peripherals such as disk drives and printers, in Valve, valves and Damper (flow), dampers, and in many other places where linear motion is required. Hydraulics, Hydraulic or Pneumatics, pneumatic cylinders inherently produce linear motion. Many other mechanisms are used to generate linear motion from a rotating motor. Types Mechanical actuators Machine, Mechanical linear actuators typically operate by conversion of rotary motion into linear motion. Conversion is commonly made via a few simple types of mechanism: * Screw (simple machine), Screw: leadscrew, screw jack, ball screw and roller screw actuators all operate on the principle of the simple machine known as the screw. By rotating the actuator's nut, the screw shaft moves in a line. * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Butterfly Valve
A butterfly valve is a valve that isolates or regulates the flow of a fluid. The closing mechanism is a disk that rotates. Principle of operation Operation is similar to that of a ball valve, which allows for quick shut off. Butterfly valves are generally favored because they cost less than other valve designs, and are lighter weight so they need less support. The disc is positioned in the center of the pipe. A rod passes through the disc to an actuator on the outside of the valve. Rotating the actuator turns the disc either parallel or perpendicular to the flow. Unlike a ball valve, the disc is always present within the flow, so it induces a pressure drop, even when open. A butterfly valve is from a family of valves called quarter-turn valves. In operation, the valve is fully open or closed when the disc is rotated a quarter turn. The "butterfly" is a metal disc mounted on a rod. When the valve is closed, the disc is turned so that it completely blocks off the passageway. Wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Airships
An airship or dirigible balloon is a type of aerostat or lighter-than-air aircraft that can navigate through the air Powered aircraft, under its own power. Aerostats gain their lift from a lifting gas that is less dense than the surrounding air. In early dirigibles, the lifting gas used was hydrogen gas, hydrogen, due to its high lifting capacity and ready availability. Helium gas has almost the same lifting capacity and is not flammable, unlike hydrogen, but is rare and relatively expensive. Significant amounts were first discovered in the United States and for a while helium was only available for airships in that country. Most airships built since the 1960s have used helium, though some have used hot air.A few airships after World War II used hydrogen. The first British airship to use helium was the Chitty Bang Bang (airship), ''Chitty Bang Bang'' of 1967. The envelope of an airship may form the gasbag, or it may contain a number of gas-filled cells. An airship also has ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Louis Philippe II, Duke Of Orléans
Louis Philippe II, Duke of Orléans (Louis Philippe Joseph; 13 April 17476 November 1793), was a major French noble who supported the French Revolution. Louis Philippe II was born at the Château de Saint-Cloud to Louis Philippe I, Duke of Chartres, and Louise Henriette de Bourbon. He was titled Duke of Montpensier at birth. When his grandfather Louis, Duke of Orléans, died in 1752, his father became the new Duke of Orléans and Louis Philippe II became Duke of Chartres. When his father died in 1785, he became Duke of Orléans and First Prince of the Blood. He was styled as Serene Highness (french: Son Altesse Sérénissime). In 1792, during the Revolution, Louis Philippe changed his name to Philippe Égalité. He was a cousin of King Louis XVI and one of the wealthiest men in France. He actively supported the Revolution of 1789, and was a strong advocate for the elimination of the present absolute monarchy in favor of a constitutional monarchy. Louis Philippe voted for the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meudon
Meudon () is a municipality in the southwestern suburbs of Paris, France. It is in the département of Hauts-de-Seine. It is located from the center of Paris. The city is known for many historic monuments and some extraordinary trees. One of them, the Imperial Cedar (), attracted the attention of Empress Eugénie and Queen Victoria. As of March 2021, the tree is in good condition, but it is threatened by real estate speculation. Another real estate project is planned for the historic park of the Napoleon III villa built by Charles Schacher. Both projects are controversial and have aroused local opposition. Geography The town of Meudon is built on the hills and valleys of the Seine. The wood of Meudon lies for the most part to the west of the town. The north-west part of Meudon, overlooking the Seine, is known as ''Bellevue'' ("beautiful view"). History At Meudon, the argile plastique clay was extensively mined in the 19th century. The first fossil of the European diatryma ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saint-Cloud
Saint-Cloud () is a commune in the western suburbs of Paris, France, from the centre of Paris. Like other communes of Hauts-de-Seine such as Marnes-la-Coquette, Neuilly-sur-Seine and Vaucresson, Saint-Cloud is one of France's wealthiest towns, with the second-highest average household income of communities with 10,000 to 50,000 households. In 2019, it had a population of 30,012. History The town is named after Clodoald, grandson of Clovis, who is supposed to have sought refuge in a hamlet on the Seine near Paris, then named Novigentum, like many other newly founded mercantile settlements outside the traditional towns. After he was canonized, the village where his tomb was located took the name of Sanctus Clodoaldus. A park contains the ruins of the Château de Saint-Cloud, built in 1572 and destroyed by fire in 1870 during the Franco-Prussian War. The château was the residence of several French rulers and served as the main country residence of the cadet Orléans line u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert Brothers
Les Frères Robert were two French brothers. Anne-Jean Robert (1758–1820) and Nicolas-Louis Robert (1760–1820) were the engineers who built the world's first hydrogen balloon for professor Jacques Charles, which flew from central Paris on 27 August 1783. They went on to build the world's first manned hydrogen balloon, and on 1 December 1783 Nicolas-Louis accompanied Jacques Charles on a 2-hour, 5-minute flight. Their barometer and thermometer made it the first balloon flight to provide meteorological measurements of the atmosphere above the Earth's surface. The brothers subsequently experimented with an elongated elliptical shape for the hydrogen envelope in a balloon they attempted to power and steer by means of oars and umbrellas. In September 1784 the brothers flew 186 km from Paris to Beuvry, the world's first flight of more than 100 km. Career Background The Robert brothers were skilled engineers with a workshop at the ''Place des Victoires'' in Paris, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jean Baptiste Meusnier
Jean Baptiste Marie Charles Meusnier de la Place (Tours, 19 June 1754 — le Pont de Cassel, near Mainz, 13 June 1793) was a French mathematician, engineer and Revolutionary general. He is best known for Meusnier's theorem on the curvature of surfaces, which he formulated while he was at the École Royale du Génie (Royal School of Engineering). He also discovered the helicoid. He worked with Lavoisier on the decomposition of water and the evolution of hydrogen. Dirigible balloon Meusnier is sometimes portrayed as the inventor of the dirigible, because of an uncompleted project he conceived in 1784, not long after the first balloon flights of the Montgolfiers, and presented to the French Academy of Sciences. This concerned an elliptical balloon (''ballonet'') 84 metres long, with a capacity of 1,700 cubic metres, powered by three propellers driven by 80 men. The basket, in the form of a boat, was suspended from the canopy on a system of three ropes. Jacques Charles and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerostat
An aerostat (, via French) is a lighter-than-air aircraft that gains its lift through the use of a buoyant gas. Aerostats include unpowered balloons and powered airships. A balloon may be free-flying or tethered. The average density of the craft is lower than the density of atmospheric air, because its main component is one or more gasbags, a lightweight skin containing a lifting gas (which could be heated air or any gas of lower density than air) to provide buoyancy, to which other components such as a gondola containing equipment or people are attached. Especially with airships, the gasbags are often protected by an outer envelope. Aerostats are so named because they use aerostatic lift which is a buoyant force that does not require movement through the surrounding air mass, resulting in VTOL ability. This contrasts with the heavy aerodynes that primarily use aerodynamic lift which requires the movement of a wing surface through the surrounding air mass. The term has also be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
