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Jetboat
A jetboat is a boat propelled by a jet of water ejected from the back of the craft. Unlike a powerboat or motorboat that uses an external propeller in the water below or behind the boat, a jetboat draws the water from under the boat through an intake and into a pump-jet inside the boat, before expelling it through a nozzle at the stern. The modern jetboat was developed by New Zealand engineer Bill Hamilton (engineer), Sir William Hamilton in the mid-1950s. His goal was a boat to run up the fast-flowing rivers of New Zealand that were too shallow for propellers. Previous attempts at waterjet propulsion had very short lifetimes, generally due to the inefficient design of the units and the fact that they offered few advantages over conventional propellers. Unlike these previous waterjet developments, such as Secondo Campini, Campini's and the Hanley Hydrojet, Hamilton had a specific need for a propulsion system to operate in very shallow water, and the waterjet proved to be the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secondo Campini
Secondo Campini (August 28, 1904 – February 7, 1980) was an Italian engineer and one of the pioneers of the jet engine. Campini was born at Bologna, Emilia-Romagna. In 1931 he wrote a proposal for the Ministry of Defence (Italy), Italian Air Ministry on the value of jet propulsion, and in 1932 demonstrated a Jetboat, jet-powered boat in Venice. With support of the Air Ministry, he began work with Italian aircraft manufacturer Caproni to develop a jet aircraft, the Caproni Campini CC.2, Caproni Campini C.C.2, which first flew in 1940. The "motorjet" that Campini developed to propel the C.C.2 is substantially different from the jet engines of today. Campini's engine used a conventional piston engine to compress air, which was then mixed with fuel and ignited. Modern jets are based on the turbojet principle, but Campini's engine was nevertheless a true jet, since it was the reactive force of the burning exhaust gases that pushed the aircraft along. After World War II, Campini emigr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TWC Waitoto River• Stewart Nimmo • MRD 0928
TWC may refer to: Organizations * Taiwan Water Corporation, a water utility company in Taiwan * Taylor Woodrow Construction, a British-based construction company, now part of Taylor Wimpey * Tech Workers Coalition, an international labor rights group seeking to organize the tech industry * Tennessee Wesleyan College, a liberal-arts college in Athens, Tennessee * Texas Workforce Commission, a governmental agency in the U.S. * Time Warner Cable, an American cable telecommunications company that existed from 1992 until its 2016 purchase by Charter Communications * Trans World Communications, the investment vehicle of businessman Owen Oyston * The Weather Company (Australian company), now known as Weatherzone, an Australian meteorological service provider * The Weinstein Company, an American film studio * Trans World Connection, an American former airline, affiliate of Trans World Airlines (TWA) * Tung Wah College, a private, self-financing college in King's Park, Kowloon, Hong Ko ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Littoral Combat Ship
A littoral combat ship (LCS) is either of two classes of relatively small surface vessels designed for littoral warfare in near-shore operations by the United States Navy. It was "envisioned to be a networked, agile, stealthy surface combatant capable of defeating anti-access and asymmetric threats in the littorals", although their ability to perform these missions in practice has been called into question. Littoral combat ships are comparable to corvettes found in other navies. The and the are the two LCS variants. Each is slightly smaller than the U.S. Navy's earlier but larger than ''Cyclone''-class patrol ships. Each has the capabilities of a small assault transport, including a flight deck and hangar for housing two SH-60 or MH-60 Seahawk helicopters, a stern ramp for operating small boats, and the cargo volume and payload to deliver a small assault force with fighting vehicles to a roll-on/roll-off port facility. Standard armaments include Mk 110 57 mm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whirlpool Jet Boat Tours In Devil's Hole Rapids In Niagara River Gorge
A whirlpool is a body of rotating water produced by opposing currents or a current running into an obstacle. Small whirlpools form when a bath or a sink is draining. More powerful ones formed in seas or oceans may be called maelstroms ( ). ''Vortex'' is the proper term for a whirlpool that has a downdraft. In narrow ocean straits with fast flowing water, whirlpools are often caused by tides. Many stories tell of ships being sucked into a maelstrom, although only smaller craft are actually in danger. Smaller whirlpools appear at Rapids, river rapids and can be observed downstream of artificial structures such as weirs and dams. Large waterfall, cataracts, such as Niagara Falls, produce strong whirlpools. Notable whirlpools Saltstraumen Saltstraumen is a narrow strait located close to the Arctic Circle, south-east of the city of Bodø (town), Bodø, Norway. It has one of the strongest tidal currents in the world. Whirlpools up to in diameter and in depth are formed when ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planing (sailing)
Planing ( ) is the mode of operation for a waterborne craft in which its weight is predominantly supported by lift (force), hydrodynamic lift, rather than Hydrostatics, hydrostatic lift (buoyancy). Many forms of marine transport make use of planing, including High-speed craft, fast ferries, racing boats, seaplanes, and water skis. Most surfboards are planing or semi-planing hulls. Beyond planing, fast vessel designs have seen a transition to hydrofoil designs. History The earliest documented planing sailboat was a proa built in 1898 by Commodore Ralph Munroe#Vessels designed, Ralph Munroe. It was capable of speeds of more than twice the hull speed. Planing a sailing Dinghy sailing, dinghy was first popularised by Uffa Fox in Britain. In 1928 Fox introduced planing to the racing world in his International 14 dinghy, ''Avenger''. That year he gained 52 first places, 2 seconds, and 3 third places out of 57 race starts. This performance was noticed by other designers who further ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wing
A wing is a type of fin that produces both Lift (force), lift and drag while moving through air. Wings are defined by two shape characteristics, an airfoil section and a planform (aeronautics), planform. Wing efficiency is expressed as lift-to-drag ratio, which compares the benefit of lift with the air resistance of a given wing shape, as it flies. Aerodynamics is the study of wing performance in air. Equivalent Foil (fluid mechanics), foils that move through water are found on Hydrofoil, hydrofoil power vessels and Sailing hydrofoil, foiling sailboats that lift out of the water at speed and on submarines that use diving planes to point the boat upwards or downwards, while running submerged. Hydrodynamics is the study of foil performance in water. Etymology and usage The word "wing" from the Old Norse ''vængr'' for many centuries referred mainly to the foremost limb (anatomy), limbs of birds (in addition to the architectural aisle). But in recent centuries the word's meaning ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrofoil
A hydrofoil is a lifting surface, or foil, that operates in water. They are similar in appearance and purpose to aerofoils used by aeroplanes. Boats that use hydrofoil technology are also simply termed hydrofoils. As a hydrofoil craft gains speed, the hydrofoils lift the boat's hull out of the water, decreasing drag and allowing greater speeds. Description The hydrofoil was created by Eric Walters. The hydrofoil usually consists of a winglike structure mounted on struts below the hull, or across the keels of a catamaran in a variety of boats (see illustration). As a hydrofoil-equipped watercraft increases in speed, the hydrofoil elements below the hull(s) develop enough lift to raise the hull out of the water, which greatly reduces hull drag. This provides a corresponding increase in speed and fuel efficiency. Wider adoption of hydrofoils is prevented by the increased complexity of building and maintaining them. Hydrofoils are generally prohibitively more expensive than ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shotover Jet, Jet Boating The Shotover River Canyons, Queenstown, New Zealand
Shotover is a hill and forest in the civil parish of Forest Hill with Shotover, in the South Oxfordshire district, in the county of Oxfordshire, England. The hill is east of Oxford. Its highest point is above sea level. Early history The toponym may be derived from the Old English , meaning "steep slope". Shotover was part of the Wychwood royal forestSherwood & Pevsner, 1974, pp. 763–765 from around the period of the Domesday Book until 1660. It was also known as the Forest of Shotover. A hill figure is recorded as having once been carved on the hill. Antiquarian John Aubrey writes: :"On Shotover Hill ear Oxfordwas heretofore (not long before the Civil Wars, in the memory of man) the effigies of a Giant cut in the earth, as the White Horse by Ashbury Park" Shotover was formerly an extra-parochial tract, in 1858 Shotover became a separate civil parish, on 25 March 1883 the parish was abolished and merged with Forest Hill. In 1851 it had a population of 163. Shotover Roa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transom (nautical)
In some boats and ships, a transom is the aft transverse surface of the hull that forms the stern of a vessel. Historically, they are a development from the canoe stern (or "double-ender") wherein which both bow and stern are pointed. Transoms add both strength and width to the stern. They may be flat or curved and they may be vertical, raked forward (known as retroussé), or raked aft. In small boats and yachts, this flat termination of the stern is typically above the waterline, but large commercial vessels often exhibit vertical transoms that dip slightly beneath the water. On cruising boats, a counter stern may be truncated to form a "truncated counter stern", in which there is a part of the stern that approximates a transom. Although that standard stern transom is typically vertical, they may be raked such that there is an overhang above the water, as at the bow. A reverse transom is angled from the waterline forwards. On smaller boats such as dinghies, transoms may be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stator
The stator is the stationary part of a rotary system, found in electric generators, electric motors, sirens, mud motors, or biological rotors (such as bacterial flagella or ATP synthase). Energy flows through a stator to or from the rotating component of the system, the rotor. In an electric motor, the stator provides a magnetic field that drives the rotating armature; in a generator, the stator converts the rotating magnetic field to electric current. In fluid powered devices, the stator guides the flow of fluid to or from the rotating part of the system. Design Motor stators are made either from iron/steel or from a printed circuit board (PCB). Originally applied to low-power applications, PCB stators can be lighter, smaller, and less noisy. One design embeds thin copper traces in the PCB stator that serve as the windings. The traces are interleaved with epoxy-glass laminates, that insulate each coil from its neighbors. An air core replaces the traditional iron core ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impeller
An impeller, or impellor, is a driven rotor used to increase the pressure and flow of a fluid. It is the opposite of a turbine, which extracts energy from, and reduces the pressure of, a flowing fluid. Strictly speaking, propellers are a sub-class of impellers where the flow both enters and leaves axially, but in many contexts the term "impeller" is reserved for ''non''-propeller rotors where the flow enters axially and leaves radially, especially when creating suction in a pump or compressor. In pumps An impeller is a rotating component of a centrifugal pump that accelerates fluid outward from the center of rotation, thus transferring energy from the motor that drives the pump to the fluid being pumped. The acceleration generates output pressure when the outward movement of the fluid is confined by the pump casing. An impeller is usually a short cylinder with an open inlet (called an eye) to accept incoming fluid, vanes to push the fluid radially, and a splined, keyed, or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
