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Marine Propulsion
Marine propulsion is the mechanism or system used to generate thrust to move a watercraft through water. While paddles and sails are still used on some smaller boats, most modern ships are propelled by mechanical systems consisting of an electric motor or internal combustion engine driving a propeller, or less frequently, in pump-jets, an impeller. Marine engineering is the discipline concerned with the engineering design process of marine propulsion systems. Human-powered watercraft, Human-powered paddles and oars, and later, sails were the first forms of marine propulsion. Rowed galleys, some equipped with sail, played an important early role in early human seafaring and naval warfare, warfare. The first advanced mechanical means of marine propulsion was the marine steam engine, introduced in the early 19th century. During the 20th century it was replaced by two-stroke diesel engine, two-stroke or four-stroke diesel engines, outboard motors, and gas turbine engines on faster sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RR Marine Spey RRHT Derby
RR, Rr or rr may refer to: Arts and entertainment * RR (film), ''RR'' (film), a 2007 experimental film by James Benning * Red Ribbon Army, a fictional army in the ''Dragon Ball'' series * Ruff Ryders Entertainment, a record label and East Coast rap collective * ''Fury from the Deep'' (production code: RR), a 1968 ''Doctor Who'' serial * RR (EP), ''RR'' (EP), a 2023 collaborative EP by Rosalía and Rauw Alejandro * RR, prefix for models of Jackson Rhoads electric guitars commissioned by guitarist Randy Rhoads Businesses and organizations * Rashtriya Rifles, an Indian counter-insurgency force * Rational Recovery, an addiction recovery program * Rekords Rekords (logo), an American record label * Rhodesia Regiment, Rhodesian Army unit * Royal Air Force (IATA airline designator) * Richard Rohac (logo), an Austrian art metal firm Language * rr (digraph) * Revised Romanization of Korean, the official Korean language romanization system in South Korea * Revised Romanization of Hangeul, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human-powered Watercraft
Human-powered watercraft are watercraft propelled only by human power, instead of being propelled by wind power (via one or more sails) or an engine. The three main methods of exerting human power are: # directly from the hands or feet, sometimes aided by swimfins; # through hand-operated oars, paddles, or poles, or; # through the feet with pedals, crankset or treadle. While most human-powered watercraft use buoyancy to maintain their position relative to the surface of the water, a few, such as human-powered hydrofoils and human-powered submarines, use hydrofoils, either alone or in addition to buoyancy. Oared craft Oars are held at one end, have a blade on the other end, and pivot in between in oarlocks. Oared craft include: * Racing shell Using oars in pairs, with one hand on each oar, is two-oar sculling. The oars may also be called sculls. Two-oared sculled craft include: * Adirondack guideboat * Banks dory, Gloucester dory, and McKenzie River dory * Din ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Battery Pack
A battery pack is a set of any number of (preferably) identical Battery (electricity), batteries or individual battery cells. They may be configured in a series, parallel or a mixture of both to deliver the desired voltage and current. The term ''battery pack'' is often used in reference to cordless tools, radio control, radio-controlled hobby toys, and battery electric vehicles. Components of battery packs include the individual batteries or cells, and the Electrical conductor, interconnects which provide electrical conductivity between them. Rechargeable battery packs often contain voltage and temperature sensors, which the battery charger uses to detect the end of charging. Interconnects are also found in batteries as they are the part which connects each cell, though batteries are most often only arranged in series strings. When a pack contains groups of cells in parallel there are differing wiring configurations which take into consideration the electrical ''balance'' of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Motor
An electric motor is a machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a electromagnetic coil, wire winding to generate Laplace force in the form of torque applied on the motor's shaft. An electric generator is mechanically identical to an electric motor, but operates in reverse, converting mechanical energy into electrical energy. Electric motors can be powered by direct current (DC) sources, such as from batteries or rectifiers, or by alternating current (AC) sources, such as a power grid, Inverter (electrical), inverters or electrical generators. Electric motors may also be classified by considerations such as power source type, construction, application and type of motion output. They can be brushed motor, brushed or brushless motor, brushless, single-phase electric power, single-phase, two-phase electric power, two-phase, or three-phase electric p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear-powered Icebreaker
A nuclear-powered icebreaker is an icebreaker with an Nuclear marine propulsion, onboard nuclear power plant that produces power for the vessel's propulsion system. Although more expensive to operate, nuclear-powered icebreakers provide a number of advantages over their diesel-powered counterparts, especially along the Northern Sea Route where diesel-powered icebreaker operations are challenging due to the heavy power demand associated with icebreaking, limited refueling infrastructure along the Siberian coast, and the endurance required. , Russia is the only country that builds and operates nuclear-powered icebreakers, having built a number of such vessels to aid shipping along the Northern Sea Route and Russian arctic outposts since the Soviet era. History of nuclear-powered icebreakers The first nuclear icebreaker was the Soviet vessel ''Lenin (1957 icebreaker), Lenin'', which was launched in 1957 as the world’s first nuclear-powered surface vessel and the first civilian-o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Warship
A warship or combatant ship is a naval ship that is used for naval warfare. Usually they belong to the navy branch of the armed forces of a nation, though they have also been operated by individuals, cooperatives and corporations. As well as being armed, warships are designed to withstand damage and are typically faster and more maneuverable than merchant ships. Unlike a merchant ship, which carries cargo, a warship typically carries only weapons, ammunition and supplies for its crew. In wartime, the distinction between warships and merchant ships is often blurred. Until the 17th century it was common for merchant ships to be pressed into naval service, and not unusual for more than half of a Naval fleet, fleet to be composed of merchant ships—there was not a large difference in construction, unlike the difference between a heavily armoured battleship and an ocean liner. Until the threat of piracy subsided in the 19th century, it was normal practice to arm larger merchant sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Marine Propulsion
Nuclear marine propulsion is Marine propulsion, propulsion of a ship or submarine with heat provided by a nuclear reactor. The power plant heats water to produce steam for a turbine used to turn the ship's propeller through a Transmission (mechanics), gearbox or through an electric generator and motor. Nuclear propulsion is used primarily within naval warships such as nuclear submarines and supercarriers. A small number of experimental civil nuclear ships have been built. Compared to oil- or coal-fuelled ships, nuclear propulsion offers the advantage of very long intervals of operation before refueling. All the fuel is contained within the nuclear reactor, so no cargo or supplies space is taken up by fuel, nor is space taken up by exhaust stacks or combustion air intakes. The low fuel cost is offset by high operating costs and investment in infrastructure, however, so nearly all nuclear-powered vessels are military. Power plants Basic operation of naval ship or submarine Most na ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gas Turbine Engine
A gas turbine or gas turbine engine is a type of Internal combustion engine#Continuous combustion, continuous flow internal combustion engine. The main parts common to all gas turbine engines form the power-producing part (known as the gas generator or core) and are, in the direction of flow: * a rotating gas compressor * a combustor * a compressor-driving turbine. Additional components have to be added to the gas generator to suit its application. Common to all is an air inlet but with different configurations to suit the requirements of marine use, land use or flight at speeds varying from stationary to supersonic. A propelling nozzle is added to produce thrust for flight. An extra turbine is added to drive a propeller (turboprop) or ducted fan (turbofan) to reduce fuel consumption (by increasing propulsive efficiency) at subsonic flight speeds. An extra turbine is also required to drive a helicopter rotor or land-vehicle transmission (turboshaft), marine propeller or electric ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Outboard Motor
An outboard motor is a propulsion system for boats, consisting of a self-contained unit that includes engine, gearbox and propeller or jet drive, designed to be affixed to the outside of the transom. They are the most common motorised method of propelling small watercraft. As well as providing propulsion, outboards provide steering control, as they are designed to pivot over their mountings and thus control the direction of thrust. The skeg also acts as a rudder when the engine is not running. Unlike inboard motors, outboard motors can be easily removed for storage or repairs. In order to eliminate the chances of hitting bottom with an outboard motor, the motor can be tilted up to an elevated position either electronically or manually. This helps when traveling through shallow waters where there may be debris that could potentially damage the motor as well as the propeller. If the electric motor required to move the pistons which raise or lower the engine is malfunction ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Four-stroke Diesel Engine
A four-stroke (also four-cycle) engine is an internal combustion (IC) engine in which the piston completes four separate strokes while turning the crankshaft. A stroke refers to the full travel of the piston along the cylinder, in either direction. The four separate strokes are termed: #Intake: Also known as induction or suction. This stroke of the piston begins at top dead center (T.D.C.) and ends at bottom dead center (B.D.C.). In this stroke the intake valve must be in the open position while the piston pulls an air-fuel mixture into the cylinder by producing a partial vacuum (negative pressure) in the cylinder through its downward motion. #Compression: This stroke begins at B.D.C, or just at the end of the suction stroke, and ends at T.D.C. In this stroke the piston compresses the air-fuel mixture in preparation for ignition during the power stroke (below). Both the intake and exhaust valves are closed during this stage. #Combustion: Also known as power or ignition. This is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Two-stroke Diesel Engine
A two-stroke diesel engine is a diesel engine that uses compression ignition in a two-stroke combustion cycle. It was invented by Hugo Güldner in 1899.Mau (1984) p.7 In compression ignition, air is first compressed and heated; fuel is then injected into the cylinder, causing it to self-ignite. This delivers a power stroke each time the piston rises and falls, without any need for the additional exhaust and induction strokes of the four-stroke cycle. History According to the engineer who drew up Rudolf Diesel‘s design for one of the first operational diesel engine, Motor 250/400, Imanuel Lauster, Diesel did not originally intend using the two-stroke principle for the diesel engine. Hugo Güldner designed what is believed to be the first operational two-stroke diesel engine in 1899, and he convinced MAN, Krupp and Diesel to fund building this engine with ℳ 10,000 each. Güldner's engine had a 175 mm work cylinder, and a 185 mm scavenging cylinder; both had a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marine Steam Engine
A marine steam engine is a steam engine that is used to power a ship or boat. This article deals mainly with marine steam engines of the reciprocating type, which were in use from the inception of the steamboat in the early 19th century to their last years of large-scale manufacture during World War II. Reciprocating steam engines were progressively replaced in marine applications during the 20th century by steam turbines and marine diesel engines. History The first commercially successful steam engine was developed by Thomas Newcomen in 1712. The steam engine improvements brought forth by James Watt in the later half of the 18th century greatly improved steam engine efficiency and allowed more compact engine arrangements. Successful adaptation of the steam engine to marine applications in England would have to wait until almost a century after Newcomen, when Scottish engineer William Symington built the world's "first practical steamboat", the '' Charlotte Dundas'', in 1802. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
