Misplaced Pages

#352647

103-667: A cowling is the removable covering of a vehicle's engine , most often found on automobiles, motorcycles, airplanes, and on outboard boat motors. On airplanes, cowlings are used to reduce drag and to cool the engine. On boats, cowlings are a cover for an outboard motor. In addition to protecting the engine, outboard motor cowlings need to admit air while keeping water out of the air intake. "Cowling" comes from "cowl", which originated from Middle English coule, from Old English cūle, from earlier cugele (“hood, cowl”). This, in turn, came from Ecclesiastical Latin cuculla (“monk's cowl”), from Latin cucullus (“hood”), of uncertain origin. In aviation,

206-464: A rocket if it is unguided. Anti-tank and anti-aircraft missiles use rocket engines to engage targets at high speed at a range of several miles, while intercontinental ballistic missiles can be used to deliver multiple nuclear warheads from thousands of miles, and anti-ballistic missiles try to stop them. Rockets have also been tested for reconnaissance , such as the Ping-Pong rocket , which

309-451: A fuel cell without side production of NO x , but this is an electrochemical engine not a heat engine. The word engine derives from Old French engin , from the Latin ingenium –the root of the word ingenious . Pre-industrial weapons of war, such as catapults , trebuchets and battering rams , were called siege engines , and knowledge of how to construct them

412-420: A multi-stage rocket , and also pioneered the concept of a rocket launch pad (a rocket standing upright against a tall building before launch having been slowly rolled into place) and the rocket-launch countdown clock. The Guardian film critic Stephen Armstrong states Lang "created the rocket industry". Lang was inspired by the 1923 book The Rocket into Interplanetary Space by Hermann Oberth, who became

515-565: A nozzle . They may also have one or more rocket engines , directional stabilization device(s) (such as fins , vernier engines or engine gimbals for thrust vectoring , gyroscopes ) and a structure (typically monocoque ) to hold these components together. Rockets intended for high speed atmospheric use also have an aerodynamic fairing such as a nose cone , which usually holds the payload. As well as these components, rockets can have any number of other components, such as wings ( rocketplanes ), parachutes , wheels ( rocket cars ), even, in

618-399: A rocket engine in the form of a fluid jet to produce thrust . For chemical rockets often the propellants are a fuel such as liquid hydrogen or kerosene burned with an oxidizer such as liquid oxygen or nitric acid to produce large volumes of very hot gas. The oxidiser is either kept separate and mixed in the combustion chamber, or comes premixed, as with solid rockets. Sometimes

721-475: A vehicle may usefully employ for propulsion, such as in space. In these circumstances, it is necessary to carry all the propellant to be used. However, they are also useful in other situations: Some military weapons use rockets to propel warheads to their targets. A rocket and its payload together are generally referred to as a missile when the weapon has a guidance system (not all missiles use rocket engines, some use other engines such as jets ) or as

824-773: A body of theory that has provided the foundation for subsequent spaceflight development. The British Royal Flying Corps designed a guided rocket during World War I . Archibald Low stated "...in 1917 the Experimental Works designed an electrically steered rocket… Rocket experiments were conducted under my own patents with the help of Cdr. Brock ." The patent "Improvements in Rockets" was raised in July 1918 but not published until February 1923 for security reasons. Firing and guidance controls could be either wire or wireless. The propulsion and guidance rocket eflux emerged from

927-415: A cardboard tube filled with black powder , but to make an efficient, accurate rocket or missile involves overcoming a number of difficult problems. The main difficulties include cooling the combustion chamber, pumping the fuel (in the case of a liquid fuel), and controlling and correcting the direction of motion. Rockets consist of a propellant , a place to put propellant (such as a propellant tank ), and

1030-432: A chemical reaction is initiated between the fuel and the oxidizer in the combustion chamber, and the resultant hot gases accelerate out of a rocket engine nozzle (or nozzles ) at the rearward-facing end of the rocket. The acceleration of these gases through the engine exerts force ("thrust") on the combustion chamber and nozzle, propelling the vehicle (according to Newton's Third Law ). This actually happens because

1133-482: A chemical reaction, but are not heat engines. Examples include: An electric motor uses electrical energy to produce mechanical energy , usually through the interaction of magnetic fields and current-carrying conductors . The reverse process, producing electrical energy from mechanical energy, is accomplished by a generator or dynamo . Traction motors used on vehicles often perform both tasks. Electric motors can be run as generators and vice versa, although this

SECTION 10

#1732792984353

1236-454: A cold cylinder, which are attached to reciprocating pistons 90° out of phase. The gas receives heat at the hot cylinder and expands, driving the piston that turns the crankshaft . After expanding and flowing through the recuperator, the gas rejects heat at the cold cylinder and the ensuing pressure drop leads to its compression by the other (displacement) piston, which forces it back to the hot cylinder. Non-thermal motors usually are powered by

1339-545: A cowling may be used for drag reduction or engine cooling by directing airflow. Examples in aviation include the NACA cowling and Townend ring . On an airplane, the cowling may also cover part of the fuselage , the nacelles , the engine mount and part of the cockpit. The cowlings and the fairings are similar, as both streamline airflow, except that cowlings are usually removable (to permit engine inspections and repairs), whereas fairings are bolted in place. Engine-facing sides of

1442-499: A decomposing monopropellant ) that emit a hot exhaust gas . A rocket engine can use gas propellants, solid propellant , liquid propellant , or a hybrid mixture of both solid and liquid . Some rockets use heat or pressure that is supplied from a source other than the chemical reaction of propellant(s), such as steam rockets , solar thermal rockets , nuclear thermal rocket engines or simple pressurized rockets such as water rocket or cold gas thrusters . With combustive propellants

1545-530: A failed launch. A successful escape of a crewed capsule occurred when Soyuz T-10 , on a mission to the Salyut 7 space station , exploded on the pad. Solid rocket propelled ejection seats are used in many military aircraft to propel crew away to safety from a vehicle when flight control is lost. A model rocket is a small rocket designed to reach low altitudes (e.g., 100–500 m (330–1,640 ft) for 30 g (1.1 oz) model) and be recovered by

1648-548: A few limited-production battery-powered electric vehicles have appeared, they have not proved competitive owing to costs and operating characteristics. In the 21st century the diesel engine has been increasing in popularity with automobile owners. However, the gasoline engine and the Diesel engine, with their new emission-control devices to improve emission performance, have not yet been significantly challenged. A number of manufacturers have introduced hybrid engines, mainly involving

1751-435: A fixed location on the ground, but would also be possible from an aircraft or ship. Rocket launch technologies include the entire set of systems needed to successfully launch a vehicle, not just the vehicle itself, but also the firing control systems , mission control center , launch pad , ground stations , and tracking stations needed for a successful launch or recovery or both. These are often collectively referred to as

1854-412: A gas as in a Stirling engine , or steam as in a steam engine or an organic liquid such as n-pentane in an Organic Rankine cycle . The fluid can be of any composition; gas is by far the most common, although even single-phase liquid is sometimes used. In the case of the steam engine, the fluid changes phases between liquid and gas. Air-breathing combustion engines are combustion engines that use

1957-464: A heat difference to induce high-amplitude sound waves. In general, thermoacoustic engines can be divided into standing wave and travelling wave devices. Stirling engines can be another form of non-combustive heat engine. They use the Stirling thermodynamic cycle to convert heat into work. An example is the alpha type Stirling engine, whereby gas flows, via a recuperator , between a hot cylinder and

2060-425: A heat engine). Chemical heat engines which employ air (ambient atmospheric gas) as a part of the fuel reaction are regarded as airbreathing engines. Chemical heat engines designed to operate outside of Earth's atmosphere (e.g. rockets , deeply submerged submarines ) need to carry an additional fuel component called the oxidizer (although there exist super-oxidizers suitable for use in rockets, such as fluorine ,

2163-561: A high pressure combustion chamber . These nozzles turn the hot gas from the combustion chamber into a cooler, hypersonic , highly directed jet of gas, more than doubling the thrust and raising the engine efficiency from 2% to 64%. His use of liquid propellants instead of gunpowder greatly lowered the weight and increased the effectiveness of rockets. In 1921, the Soviet research and development laboratory Gas Dynamics Laboratory began developing solid-propellant rockets , which resulted in

SECTION 20

#1732792984353

2266-460: A large scale required efficient electrical generators and electrical distribution networks. To reduce the electric energy consumption from motors and their associated carbon footprints , various regulatory authorities in many countries have introduced and implemented legislation to encourage the manufacture and use of higher efficiency electric motors. A well-designed motor can convert over 90% of its input energy into useful power for decades. When

2369-489: A majority of the models. Several three-cylinder, two-stroke-cycle models were built while most engines had straight or in-line cylinders. There were several V-type models and horizontally opposed two- and four-cylinder makes too. Overhead camshafts were frequently employed. The smaller engines were commonly air-cooled and located at the rear of the vehicle; compression ratios were relatively low. The 1970s and 1980s saw an increased interest in improved fuel economy , which caused

2472-438: A more powerful oxidant than oxygen itself); or the application needs to obtain heat by non-chemical means, such as by means of nuclear reactions . All chemically fueled heat engines emit exhaust gases. The cleanest engines emit water only. Strict zero-emissions generally means zero emissions other than water and water vapour. Only heat engines which combust pure hydrogen (fuel) and pure oxygen (oxidizer) achieve zero-emission by

2575-560: A nuclear power plant uses the heat from the nuclear reaction to produce steam and drive a steam engine, or a gas turbine in a rocket engine may be driven by decomposing hydrogen peroxide . Apart from the different energy source, the engine is often engineered much the same as an internal or external combustion engine. Another group of noncombustive engines includes thermoacoustic heat engines (sometimes called "TA engines") which are thermoacoustic devices that use high-amplitude sound waves to pump heat from one place to another, or conversely use

2678-543: A pointed tip traveling at high speeds, model rocketry historically has proven to be a very safe hobby and has been credited as a significant source of inspiration for children who eventually become scientists and engineers . Hobbyists build and fly a wide variety of model rockets. Many companies produce model rocket kits and parts but due to their inherent simplicity some hobbyists have been known to make rockets out of almost anything. Rockets are also used in some types of consumer and professional fireworks . A water rocket

2781-563: A pressure just above atmospheric to drive the piston helped by a partial vacuum. Improving on the design of the 1712 Newcomen steam engine , the Watt steam engine, developed sporadically from 1763 to 1775, was a great step in the development of the steam engine. Offering a dramatic increase in fuel efficiency , James Watt 's design became synonymous with steam engines, due in no small part to his business partner, Matthew Boulton . It enabled rapid development of efficient semi-automated factories on

2884-564: A previously unimaginable scale in places where waterpower was not available. Later development led to steam locomotives and great expansion of railway transportation . As for internal combustion piston engines , these were tested in France in 1807 by de Rivaz and independently, by the Niépce brothers . They were theoretically advanced by Carnot in 1824. In 1853–57 Eugenio Barsanti and Felice Matteucci invented and patented an engine using

2987-614: A rail at extremely high speed. The world record for this is Mach 8.5. Larger rockets are normally launched from a launch pad that provides stable support until a few seconds after ignition. Due to their high exhaust velocity—2,500 to 4,500 m/s (9,000 to 16,200 km/h; 5,600 to 10,100 mph)—rockets are particularly useful when very high speeds are required, such as orbital speed at approximately 7,800 m/s (28,000 km/h; 17,000 mph). Spacecraft delivered into orbital trajectories become artificial satellites , which are used for many commercial purposes. Indeed, rockets remain

3090-608: A railroad electric locomotive , rather than an electric motor. Some motors are powered by potential or kinetic energy, for example some funiculars , gravity plane and ropeway conveyors have used the energy from moving water or rocks, and some clocks have a weight that falls under gravity. Other forms of potential energy include compressed gases (such as pneumatic motors ), springs ( clockwork motors ) and elastic bands . Historic military siege engines included large catapults , trebuchets , and (to some extent) battering rams were powered by potential energy. A pneumatic motor

3193-693: A reference to 1264, recording that the "ground-rat", a type of firework , had frightened the Empress-Mother Gongsheng at a feast held in her honor by her son the Emperor Lizong . Subsequently, rockets are included in the military treatise Huolongjing , also known as the Fire Drake Manual, written by the Chinese artillery officer Jiao Yu in the mid-14th century. This text mentions the first known multistage rocket ,

Cowling - Misplaced Pages Continue

3296-569: A return to smaller V-6 and four-cylinder layouts, with as many as five valves per cylinder to improve efficiency. The Bugatti Veyron 16.4 operates with a W16 engine , meaning that two V8 cylinder layouts are positioned next to each other to create the W ;shape sharing the same crankshaft. The largest internal combustion engine ever built is the Wärtsilä-Sulzer RTA96-C , a 14-cylinder, 2-stroke turbocharged diesel engine that

3399-504: A sense, a person ( rocket belt ). Vehicles frequently possess navigation systems and guidance systems that typically use satellite navigation and inertial navigation systems . Rocket engines employ the principle of jet propulsion . The rocket engines powering rockets come in a great variety of different types; a comprehensive list can be found in the main article, Rocket engine . Most current rockets are chemically powered rockets (usually internal combustion engines , but some employ

3502-724: A small gasoline engine coupled with an electric motor and with a large battery bank, these are starting to become a popular option because of their environment awareness. Exhaust gas from a spark ignition engine consists of the following: nitrogen 70 to 75% (by volume), water vapor 10 to 12%, carbon dioxide 10 to 13.5%, hydrogen 0.5 to 2%, oxygen 0.2 to 2%, carbon monoxide : 0.1 to 6%, unburnt hydrocarbons and partial oxidation products (e.g. aldehydes ) 0.5 to 1%, nitrogen monoxide 0.01 to 0.4%, nitrous oxide <100 ppm, sulfur dioxide 15 to 60 ppm, traces of other compounds such as fuel additives and lubricants, also halogen and metallic compounds, and other particles. Carbon monoxide

3605-454: A solid combination of fuel with oxidizer ( solid fuel ), or solid fuel with liquid or gaseous oxidizer ( hybrid propellant system ). Chemical rockets store a large amount of energy in an easily released form, and can be very dangerous. However, careful design, testing, construction and use minimizes risks. In China, gunpowder -powered rockets evolved in medieval China under the Song dynasty by

3708-453: A source of water power to provide additional power to watermills and water-raising machines. In the medieval Islamic world , such advances made it possible to mechanize many industrial tasks previously carried out by manual labour . In 1206, al-Jazari employed a crank - conrod system for two of his water-raising machines. A rudimentary steam turbine device was described by Taqi al-Din in 1551 and by Giovanni Branca in 1629. In

3811-429: A strict definition (in practice, one type of rocket engine). If hydrogen is burnt in combination with air (all airbreathing engines), a side reaction occurs between atmospheric oxygen and atmospheric nitrogen resulting in small emissions of NO x . If a hydrocarbon (such as alcohol or gasoline) is burnt as fuel, CO 2 , a greenhouse gas , is emitted. Hydrogen and oxygen from air can be reacted into water by

3914-431: A torque include the familiar automobile gasoline and diesel engines, as well as turboshafts . Examples of engines which produce thrust include turbofans and rockets . When the internal combustion engine was invented, the term motor was initially used to distinguish it from the steam engine—which was in wide use at the time, powering locomotives and other vehicles such as steam rollers . The term motor derives from

4017-724: A variety of means. According to the United States National Association of Rocketry (nar) Safety Code, model rockets are constructed of paper, wood, plastic and other lightweight materials. The code also provides guidelines for motor use, launch site selection, launch methods, launcher placement, recovery system design and deployment and more. Since the early 1960s, a copy of the Model Rocket Safety Code has been provided with most model rocket kits and motors. Despite its inherent association with extremely flammable substances and objects with

4120-561: A water-powered mill was built in Kaberia of the kingdom of Mithridates during the 1st century BC. Use of water wheels in mills spread throughout the Roman Empire over the next few centuries. Some were quite complex, with aqueducts , dams , and sluices to maintain and channel the water, along with systems of gears , or toothed-wheels made of wood and metal to regulate the speed of rotation. More sophisticated small devices, such as

4223-407: Is a vehicle that uses jet propulsion to accelerate without using any surrounding air . A rocket engine produces thrust by reaction to exhaust expelled at high speed. Rocket engines work entirely from propellant carried within the vehicle; therefore a rocket can fly in the vacuum of space. Rockets work more efficiently in a vacuum and incur a loss of thrust due to the opposing pressure of

Cowling - Misplaced Pages Continue

4326-416: Is a machine that converts potential energy in the form of compressed air into mechanical work . Pneumatic motors generally convert the compressed air to mechanical work through either linear or rotary motion. Linear motion can come from either a diaphragm or piston actuator, while rotary motion is supplied by either a vane type air motor or piston air motor. Pneumatic motors have found widespread success in

4429-416: Is a type of model rocket using water as its reaction mass. The pressure vessel (the engine of the rocket) is usually a used plastic soft drink bottle. The water is forced out by a pressurized gas, typically compressed air. It is an example of Newton's third law of motion. The scale of amateur rocketry can range from a small rocket launched in one's own backyard to a rocket that reached space. Amateur rocketry

4532-534: Is highly toxic, and can cause carbon monoxide poisoning , so it is important to avoid any build-up of the gas in a confined space. Catalytic converters can reduce toxic emissions, but not eliminate them. Also, resulting greenhouse gas emissions, chiefly carbon dioxide , from the widespread use of engines in the modern industrialized world is contributing to the global greenhouse effect – a primary concern regarding global warming . Some engines convert heat from noncombustive processes into mechanical work, for example

4635-406: Is less necessary, a pressurised fluid is used as propellant that simply escapes the spacecraft through a propelling nozzle. The first liquid-fuel rocket , constructed by Robert H. Goddard , differed significantly from modern rockets. The rocket engine was at the top and the fuel tank at the bottom of the rocket, based on Goddard's belief that the rocket would achieve stability by "hanging" from

4738-710: Is not always practical. Electric motors are ubiquitous, being found in applications as diverse as industrial fans, blowers and pumps, machine tools, household appliances, power tools , and disk drives . They may be powered by direct current (for example a battery powered portable device or motor vehicle), or by alternating current from a central electrical distribution grid. The smallest motors may be found in electric wristwatches. Medium-size motors of highly standardized dimensions and characteristics provide convenient mechanical power for industrial uses. The very largest electric motors are used for propulsion of large ships, and for such purposes as pipeline compressors, with ratings in

4841-428: Is reached with a coolant temperature of around 110 °C (230 °F). Earlier automobile engine development produced a much larger range of engines than is in common use today. Engines have ranged from 1- to 16-cylinder designs with corresponding differences in overall size, weight, engine displacement , and cylinder bores . Four cylinders and power ratings from 19 to 120 hp (14 to 90 kW) were followed in

4944-558: Is split into three categories according to total engine impulse : low-power, mid-power, and high-power . Hydrogen peroxide rockets are used to power jet packs , and have been used to power cars and a rocket car holds the all time (albeit unofficial) drag racing record. Corpulent Stump is the most powerful non-commercial rocket ever launched on an Aerotech engine in the United Kingdom. Launches for orbital spaceflights , or into interplanetary space , are usually from

5047-534: Is then cooled, compressed and reused (closed cycle), or (less commonly) dumped, and cool fluid pulled in (open cycle air engine). " Combustion " refers to burning fuel with an oxidizer , to supply the heat. Engines of similar (or even identical) configuration and operation may use a supply of heat from other sources such as nuclear, solar, geothermal or exothermic reactions not involving combustion; but are not then strictly classed as external combustion engines, but as external thermal engines. The working fluid can be

5150-496: The 'fire-dragon issuing from the water' (Huo long chu shui), thought to have been used by the Chinese navy. Medieval and early modern rockets were used militarily as incendiary weapons in sieges . Between 1270 and 1280, Hasan al-Rammah wrote al-furusiyyah wa al-manasib al-harbiyya ( The Book of Military Horsemanship and Ingenious War Devices ), which included 107 gunpowder recipes, 22 of them for rockets. In Europe, Roger Bacon mentioned firecrackers made in various parts of

5253-707: The Antikythera Mechanism used complex trains of gears and dials to act as calendars or predict astronomical events. In a poem by Ausonius in the 4th century AD, he mentions a stone-cutting saw powered by water. Hero of Alexandria is credited with many such wind and steam powered machines in the 1st century AD, including the Aeolipile and the vending machine , often these machines were associated with worship, such as animated altars and automated temple doors. Medieval Muslim engineers employed gears in mills and water-raising machines, and used dams as

SECTION 50

#1732792984353

5356-616: The Italian rocchetta , meaning "bobbin" or "little spindle", given due to the similarity in shape to the bobbin or spool used to hold the thread from a spinning wheel. Leonhard Fronsperger and Conrad Haas adopted the Italian term into German in the mid-16th century; "rocket" appears in English by the early 17th century. Artis Magnae Artilleriae pars prima , an important early modern work on rocket artillery , by Casimir Siemienowicz ,

5459-557: The Saturn V and Soyuz , have launch escape systems . This is a small, usually solid rocket that is capable of pulling the crewed capsule away from the main vehicle towards safety at a moments notice. These types of systems have been operated several times, both in testing and in flight, and operated correctly each time. This was the case when the Safety Assurance System (Soviet nomenclature) successfully pulled away

5562-662: The Volkswagen Beetle , the Citroën 2CV , some Porsche and Subaru cars, many BMW and Honda motorcycles . Opposed four- and six-cylinder engines continue to be used as a power source in small, propeller-driven aircraft . The continued use of internal combustion engines in automobiles is partly due to the improvement of engine control systems, such as on-board computers providing engine management processes, and electronically controlled fuel injection. Forced air induction by turbocharging and supercharging have increased

5665-407: The club and oar (examples of the lever ), are prehistoric . More complex engines using human power , animal power , water power , wind power and even steam power date back to antiquity. Human power was focused by the use of simple engines, such as the capstan , windlass or treadmill , and with ropes , pulleys , and block and tackle arrangements; this power was transmitted usually with

5768-733: The combustion of a fuel causes rapid pressurisation of the gaseous combustion products in the combustion chamber, causing them to expand and drive a piston , which turns a crankshaft . Unlike internal combustion engines, a reaction engine (such as a jet engine ) produces thrust by expelling reaction mass , in accordance with Newton's third law of motion . Apart from heat engines, electric motors convert electrical energy into mechanical motion, pneumatic motors use compressed air , and clockwork motors in wind-up toys use elastic energy . In biological systems, molecular motors , like myosins in muscles , use chemical energy to create forces and ultimately motion (a chemical engine, but not

5871-399: The oxygen in atmospheric air to oxidise ('burn') the fuel, rather than carrying an oxidiser , as in a rocket . Theoretically, this should result in a better specific impulse than for rocket engines. A continuous stream of air flows through the air-breathing engine. This air is compressed, mixed with fuel, ignited and expelled as the exhaust gas . In reaction engines , the majority of

5974-429: The pistons or turbine blades or a nozzle , and by moving it over a distance, generates mechanical work . An external combustion engine (EC engine) is a heat engine where an internal working fluid is heated by combustion of an external source, through the engine wall or a heat exchanger . The fluid then, by expanding and acting on the mechanism of the engine produces motion and usable work . The fluid

6077-471: The 13th century, the solid rocket motor was invented in China. Driven by gunpowder, this simplest form of internal combustion engine was unable to deliver sustained power, but was useful for propelling weaponry at high speeds towards enemies in battle and for fireworks . After invention, this innovation spread throughout Europe. The Watt steam engine was the first type of steam engine to make use of steam at

6180-569: The 13th century. They also developed an early form of multiple rocket launcher during this time. The Mongols adopted Chinese rocket technology and the invention spread via the Mongol invasions to the Middle East and to Europe in the mid-13th century. According to Joseph Needham, the Song navy used rockets in a military exercise dated to 1245. Internal-combustion rocket propulsion is mentioned in

6283-572: The Congreve rocket in 1865. William Leitch first proposed the concept of using rockets to enable human spaceflight in 1861. Leitch's rocket spaceflight description was first provided in his 1861 essay "A Journey Through Space", which was later published in his book God's Glory in the Heavens (1862). Konstantin Tsiolkovsky later (in 1903) also conceived this idea, and extensively developed

SECTION 60

#1732792984353

6386-571: The L3 capsule during three of the four failed launches of the Soviet Moon rocket, N1 vehicles 3L, 5L and 7L . In all three cases the capsule, albeit uncrewed, was saved from destruction. Only the three aforementioned N1 rockets had functional Safety Assurance Systems. The outstanding vehicle, 6L , had dummy upper stages and therefore no escape system giving the N1 booster a 100% success rate for egress from

6489-521: The Latin verb moto which means 'to set in motion', or 'maintain motion'. Thus a motor is a device that imparts motion. Motor and engine are interchangeable in standard English. In some engineering jargons, the two words have different meanings, in which engine is a device that burns or otherwise consumes fuel, changing its chemical composition, and a motor is a device driven by electricity , air , or hydraulic pressure, which does not change

6592-634: The Soviet Katyusha rocket in the artillery role, and the American anti tank bazooka projectile. These used solid chemical propellants. The Americans captured a large number of German rocket scientists , including Wernher von Braun, in 1945, and brought them to the United States as part of Operation Paperclip . After World War II scientists used rockets to study high-altitude conditions, by radio telemetry of temperature and pressure of

6695-779: The Soviet Union ( Vostok , Soyuz , Proton ) and in the United States (e.g. the X-15 ). Rockets came into use for space exploration . American crewed programs ( Project Mercury , Project Gemini and later the Apollo programme ) culminated in 1969 with the first crewed landing on the Moon – using equipment launched by the Saturn V rocket. Rocket vehicles are often constructed in the archetypal tall thin "rocket" shape that takes off vertically, but there are actually many different types of rockets including: A rocket design can be as simple as

6798-843: The air passes the free-standing cylinders is greatly reduced. The sum of all these effects reduces drag by as much as 60 percent. After tests in 1932 proved the effectiveness of NACA cowlings, almost every radial-engined aircraft were equipped with them. Engine Available energy sources include potential energy (e.g. energy of the Earth's gravitational field as exploited in hydroelectric power generation ), heat energy (e.g. geothermal ), chemical energy , electric potential and nuclear energy (from nuclear fission or nuclear fusion ). Many of these processes generate heat as an intermediate energy form; thus heat engines have special importance. Some natural processes, such as atmospheric convection cells convert environmental heat into motion (e.g. in

6901-689: The atmosphere, detection of cosmic rays , and further techniques; note too the Bell X-1 , the first crewed vehicle to break the sound barrier (1947). Independently, in the Soviet Union's space program research continued under the leadership of the chief designer Sergei Korolev (1907–1966). During the Cold War rockets became extremely important militarily with the development of modern intercontinental ballistic missiles (ICBMs). The 1960s saw rapid development of rocket technology, particularly in

7004-419: The atmosphere. Multistage rockets are capable of attaining escape velocity from Earth and therefore can achieve unlimited maximum altitude. Compared with airbreathing engines , rockets are lightweight and powerful and capable of generating large accelerations . To control their flight, rockets rely on momentum , airfoils , auxiliary reaction engines , gimballed thrust , momentum wheels , deflection of

7107-436: The chemical composition of its energy source. However, rocketry uses the term rocket motor , even though they consume fuel. A heat engine may also serve as a prime mover —a component that transforms the flow or changes in pressure of a fluid into mechanical energy . An automobile powered by an internal combustion engine may make use of various motors and pumps, but ultimately all such devices derive their power from

7210-447: The combustion energy (heat) exits the engine as exhaust gas, which provides thrust directly. Typical air-breathing engines include: The operation of engines typically has a negative impact upon air quality and ambient sound levels . There has been a growing emphasis on the pollution producing features of automotive power systems. This has created new interest in alternate power sources and internal-combustion engine refinements. Though

7313-447: The cowling must be made of metal. On jets, they are used as an air intake for jet engines. Cowlings may also be used for decorative purposes. On piston-engined planes, the cowling constitutes a symmetric, circular airfoil, in contrast to the planar airfoil of airplane wings. It directs cool air to flow through the engine where it is routed across the engine's hottest parts, that is, the cylinders and heads . Furthermore, turbulence after

7416-410: The deflecting cowl at the nose. In 1920, Professor Robert Goddard of Clark University published proposed improvements to rocket technology in A Method of Reaching Extreme Altitudes . In 1923, Hermann Oberth (1894–1989) published Die Rakete zu den Planetenräumen ( The Rocket into Planetary Space ). Modern rockets originated in 1926 when Goddard attached a supersonic ( de Laval ) nozzle to

7519-463: The dynamics of rocket propulsion is due to William Moore (1813). In 1814, Congreve published a book in which he discussed the use of multiple rocket launching apparatus. In 1815 Alexander Dmitrievich Zasyadko constructed rocket-launching platforms, which allowed rockets to be fired in salvos (6 rockets at a time), and gun-laying devices. William Hale in 1844 greatly increased the accuracy of rocket artillery. Edward Mounier Boxer further improved

7622-489: The efficiency of a motor is raised by even a few percentage points, the savings, in kilowatt hours (and therefore in cost), are enormous. The electrical energy efficiency of a typical industrial induction motor can be improved by: 1) reducing the electrical losses in the stator windings (e.g., by increasing the cross-sectional area of the conductor , improving the winding technique, and using materials with higher electrical conductivities , such as copper ), 2) reducing

7725-496: The electrical losses in the rotor coil or casting (e.g., by using materials with higher electrical conductivities, such as copper), 3) reducing magnetic losses by using better quality magnetic steel , 4) improving the aerodynamics of motors to reduce mechanical windage losses, 5) improving bearings to reduce friction losses , and 6) minimizing manufacturing tolerances . For further discussion on this subject, see Premium efficiency ). By convention, electric engine refers to

7828-425: The engine like a pendulum in flight. However, the rocket veered off course and crashed 184 feet (56 m) away from the launch site , indicating that the rocket was no more stable than one with the rocket engine at the base. Rockets or other similar reaction devices carrying their own propellant must be used when there is no other substance (land, water, or air) or force ( gravity , magnetism , light ) that

7931-404: The engine. Another way of looking at it is that a motor receives power from an external source, and then converts it into mechanical energy, while an engine creates power from pressure (derived directly from the explosive force of combustion or other chemical reaction, or secondarily from the action of some such force on other substances such as air, water, or steam). Simple machines , such as

8034-609: The exhaust stream , propellant flow, spin , or gravity . Rockets for military and recreational uses date back to at least 13th-century China . Significant scientific, interplanetary and industrial use did not occur until the 20th century, when rocketry was the enabling technology for the Space Age , including setting foot on the Moon . Rockets are now used for fireworks , missiles and other weaponry , ejection seats , launch vehicles for artificial satellites , human spaceflight , and space exploration . Chemical rockets are

8137-698: The film's scientific adviser and later an important figure in the team that developed the V-2 rocket. The film was thought to be so realistic that it was banned by the Nazis when they came to power for fear it would reveal secrets about the V-2 rockets. In 1943 production of the V-2 rocket began in Germany. It was designed by the Peenemünde Army Research Center with Wernher von Braun serving as

8240-636: The first half of the 20th century, a trend of increasing engine power occurred, particularly in the U.S. models. Design changes incorporated all known methods of increasing engine capacity, including increasing the pressure in the cylinders to improve efficiency, increasing the size of the engine, and increasing the rate at which the engine produces work. The higher forces and pressures created by these changes created engine vibration and size problems that led to stiffer, more compact engines with V and opposed cylinder layouts replacing longer straight-line arrangements. Optimal combustion efficiency in passenger vehicles

8343-460: The first launch in 1928, which flew for approximately 1,300 metres. These rockets were used in 1931 for the world's first successful use of rockets for jet-assisted takeoff of aircraft and became the prototypes for the Katyusha rocket launcher , which were used during World War II . In 1929, Fritz Lang 's German science fiction film Woman in the Moon was released. It showcased the use of

8446-410: The force (pressure times area) on the combustion chamber wall is unbalanced by the nozzle opening; this is not the case in any other direction. The shape of the nozzle also generates force by directing the exhaust gas along the axis of the rocket. Rocket propellant is mass that is stored, usually in some form of propellant tank or casing, prior to being used as the propulsive mass that is ejected from

8549-691: The forces multiplied and the speed reduced . These were used in cranes and aboard ships in Ancient Greece , as well as in mines , water pumps and siege engines in Ancient Rome . The writers of those times, including Vitruvius , Frontinus and Pliny the Elder , treat these engines as commonplace, so their invention may be more ancient. By the 1st century AD, cattle and horses were used in mills , driving machines similar to those powered by humans in earlier times. According to Strabo ,

8652-403: The form of rising air currents). Mechanical energy is of particular importance in transportation , but also plays a role in many industrial processes such as cutting, grinding, crushing, and mixing. Mechanical heat engines convert heat into work via various thermodynamic processes. The internal combustion engine is perhaps the most common example of a mechanical heat engine in which heat from

8755-528: The free-piston principle that was possibly the first 4-cycle engine. The invention of an internal combustion engine which was later commercially successful was made during 1860 by Etienne Lenoir . In 1877, the Otto cycle was capable of giving a far higher power-to-weight ratio than steam engines and worked much better for many transportation applications such as cars and aircraft. The first commercially successful automobile, created by Karl Benz , added to

8858-531: The hand-held tool industry and continual attempts are being made to expand their use to the transportation industry. However, pneumatic motors must overcome efficiency deficiencies before being seen as a viable option in the transportation industry. A hydraulic motor derives its power from a pressurized liquid . This type of engine is used to move heavy loads and drive machinery. Rocket A rocket (from Italian : rocchetto , lit.   ''bobbin/spool'', and so named for its shape)

8961-411: The heat of a combustion process. The internal combustion engine is an engine in which the combustion of a fuel (generally, fossil fuel ) occurs with an oxidizer (usually air) in a combustion chamber . In an internal combustion engine the expansion of the high temperature and high pressure gases, which are produced by the combustion, directly applies force to components of the engine, such as

9064-462: The interest in light and powerful engines. The lightweight gasoline internal combustion engine, operating on a four-stroke Otto cycle, has been the most successful for light automobiles, while the thermally more-efficient Diesel engine is used for trucks and buses. However, in recent years, turbocharged Diesel engines have become increasingly popular in automobiles, especially outside of the United States, even for quite small cars. In 1896, Karl Benz

9167-482: The most common type of high power rocket, typically creating a high speed exhaust by the combustion of fuel with an oxidizer . The stored propellant can be a simple pressurized gas or a single liquid fuel that disassociates in the presence of a catalyst ( monopropellant ), two liquids that spontaneously react on contact ( hypergolic propellants ), two liquids that must be ignited to react (like kerosene (RP1) and liquid oxygen, used in most liquid-propellant rockets ),

9270-479: The only way to launch spacecraft into orbit and beyond. They are also used to rapidly accelerate spacecraft when they change orbits or de-orbit for landing . Also, a rocket may be used to soften a hard parachute landing immediately before touchdown (see retrorocket ). Rockets were used to propel a line to a stricken ship so that a Breeches buoy can be used to rescue those on board. Rockets are also used to launch emergency flares . Some crewed rockets, notably

9373-649: The power output of smaller displacement engines that are lighter in weight and more fuel-efficient at normal cruise power.. Similar changes have been applied to smaller Diesel engines, giving them almost the same performance characteristics as gasoline engines. This is especially evident with the popularity of smaller diesel engine-propelled cars in Europe. Diesel engines produce lower hydrocarbon and CO 2 emissions, but greater particulate and NO x pollution, than gasoline engines. Diesel engines are also 40% more fuel efficient than comparable gasoline engines. In

9476-470: The propellant is not burned but still undergoes a chemical reaction, and can be a 'monopropellant' such as hydrazine , nitrous oxide or hydrogen peroxide that can be catalytically decomposed to hot gas. Alternatively, an inert propellant can be used that can be externally heated, such as in steam rocket , solar thermal rocket or nuclear thermal rockets . For smaller, low performance rockets such as attitude control thrusters where high performance

9579-549: The technical director. The V-2 became the first artificial object to travel into space by crossing the Kármán line with the vertical launch of MW 18014 on 20 June 1944. Doug Millard, space historian and curator of space technology at the Science Museum, London , where a V-2 is exhibited in the main exhibition hall, states: "The V-2 was a quantum leap of technological change. We got to the Moon using V-2 technology but this

9682-442: The thousands of kilowatts . Electric motors may be classified by the source of electric power, by their internal construction, and by their application. The physical principle of production of mechanical force by the interactions of an electric current and a magnetic field was known as early as 1821. Electric motors of increasing efficiency were constructed throughout the 19th century, but commercial exploitation of electric motors on

9785-519: The world in the Opus Majus of 1267. Between 1280 and 1300, the Liber Ignium gave instructions for constructing devices that are similar to firecrackers based on second hand accounts. Konrad Kyeser described rockets in his military treatise Bellifortis around 1405. Giovanni Fontana , a Paduan engineer in 1420, created rocket-propelled animal figures. The name "rocket" comes from

9888-523: Was designed to power the Emma Mærsk , the largest container ship in the world when launched in 2006. This engine has a mass of 2,300 tonnes, and when running at 102 rpm (1.7 Hz) produces over 80 MW, and can use up to 250 tonnes of fuel per day. An engine can be put into a category according to two criteria: the form of energy it accepts in order to create motion, and the type of motion it outputs. Combustion engines are heat engines driven by

9991-535: Was fielded in the Napoleonic Wars . It was Congreve rockets to which Francis Scott Key was referring, when he wrote of the "rockets' red glare" while held captive on a British ship that was laying siege to Fort McHenry in 1814. Together, the Mysorean and British innovations increased the effective range of military rockets from 100 to 2,000 yards (91 to 1,829 m). The first mathematical treatment of

10094-531: Was first printed in Amsterdam in 1650. The Mysorean rockets were the first successful iron-cased rockets, developed in the late 18th century in the Kingdom of Mysore (part of present-day India) under the rule of Hyder Ali . The Congreve rocket was a British weapon designed and developed by Sir William Congreve in 1804. This rocket was based directly on the Mysorean rockets, used compressed powder and

10197-436: Was granted a patent for his design of the first engine with horizontally opposed pistons. His design created an engine in which the corresponding pistons move in horizontal cylinders and reach top dead center simultaneously, thus automatically balancing each other with respect to their individual momentum. Engines of this design are often referred to as “flat” or “boxer” engines due to their shape and low profile. They were used in

10300-446: Was launched to surveil enemy targets, however, recon rockets have never come into wide use in the military. Sounding rockets are commonly used to carry instruments that take readings from 50 kilometers (31 mi) to 1,500 kilometers (930 mi) above the surface of the Earth. The first images of Earth from space were obtained from a V-2 rocket in 1946 ( flight #13 ). Rocket engines are also used to propel rocket sleds along

10403-463: Was merely a water pump, with the engine being transported to the fire by horses. In modern usage, the term engine typically describes devices, like steam engines and internal combustion engines, that burn or otherwise consume fuel to perform mechanical work by exerting a torque or linear force (usually in the form of thrust ). Devices converting heat energy into motion are commonly referred to simply as engines . Examples of engines which exert

10506-473: Was often treated as a military secret. The word gin , as in cotton gin , is short for engine . Most mechanical devices invented during the Industrial Revolution were described as engines—the steam engine being a notable example. However, the original steam engines, such as those by Thomas Savery , were not mechanical engines but pumps. In this manner, a fire engine in its original form

10609-645: Was technology that was developed with massive resources, including some particularly grim ones. The V-2 programme was hugely expensive in terms of lives, with the Nazis using slave labour to manufacture these rockets". In parallel with the German guided-missile programme, rockets were also used on aircraft , either for assisting horizontal take-off ( RATO ), vertical take-off ( Bachem Ba 349 "Natter") or for powering them ( Me 163 , see list of World War II guided missiles of Germany ). The Allies' rocket programs were less technological, relying mostly on unguided missiles like

#352647