A piston is a component of reciprocating engines, reciprocating pumps, gas compressors and pneumatic cylinders, among other similar mechanisms. It is the moving component, contained by a cylinder and is made gas-tight by piston rings. In an engine, its purpose is to transfer force from expanding gas in the cylinder to the crankshaft via a piston rod and/or connecting rod. In a pump, the function is reversed and force is transferred from the crankshaft to the piston for the purpose of compressing or ejecting the fluid in the cylinder. In some engines, the piston acts as a valve by covering and uncovering ports in the cylinder. An internal combustion engine is acted upon by the pressure of the expanding combustion gases in the combustion chamber space at the top of the cylinder; this force acts downwards through the connecting rod and onto the crankshaft. The connecting rod is attached to the piston by a swivelling gudgeon pin; this pin is mounted within the piston: unlike the steam engine, there is no piston rod or crosshead.
The pin itself is of hardened steel and is fixed in the piston, but free to move in the connecting rod. A few designs use a'fully floating' design, loose in both components. All pins must be prevented from moving sideways and the ends of the pin digging into the cylinder wall by circlips. Gas sealing is achieved by the use of piston rings; these are a number of narrow iron rings, fitted loosely into grooves in the piston, just below the crown. The rings are split at a point in the rim, allowing them to press against the cylinder with a light spring pressure. Two types of ring are used: the upper rings have solid faces and provide gas sealing. There are many detail design features associated with piston rings. Pistons are cast from aluminium alloys. For better strength and fatigue life, some racing pistons may be forged instead. Billet pistons are used in racing engines because they do not rely on the size and architecture of available forgings, allowing for last-minute design changes. Although not visible to the naked eye, pistons themselves are designed with a certain level of ovality and profile taper, meaning they are not round, their diameter is larger near the bottom of the skirt than at the crown.
Early pistons were of cast iron, but there were obvious benefits for engine balancing if a lighter alloy could be used. To produce pistons that could survive engine combustion temperatures, it was necessary to develop new alloys such as Y alloy and Hiduminium for use as pistons. A few early gas engines had double-acting cylinders, but otherwise all internal combustion engine pistons are single-acting. During World War II, the US submarine Pompano was fitted with a prototype of the infamously unreliable H. O. R. Double-acting two-stroke diesel engine. Although compact, for use in a cramped submarine, this design of engine was not repeated. Media related to Internal combustion engine pistons at Wikimedia Commons Trunk pistons are long relative to their diameter, they act both as cylindrical crosshead. As the connecting rod is angled for much of its rotation, there is a side force that reacts along the side of the piston against the cylinder wall. A longer piston helps to support this. Trunk pistons have been a common design of piston since the early days of the reciprocating internal combustion engine.
They were used for both petrol and diesel engines, although high speed engines have now adopted the lighter weight slipper piston. A characteristic of most trunk pistons for diesel engines, is that they have a groove for an oil ring below the gudgeon pin, in addition to the rings between the gudgeon pin and crown; the name ` trunk piston' derives from an early design of marine steam engine. To make these more compact, they avoided the steam engine's usual piston rod with separate crosshead and were instead the first engine design to place the gudgeon pin directly within the piston. Otherwise these trunk engine pistons bore little resemblance to the trunk piston. Their'trunk' was a narrow cylinder mounted in the centre of the piston. Media related to Trunk pistons at Wikimedia Commons Large slow-speed Diesel engines may require additional support for the side forces on the piston; these engines use crosshead pistons. The main piston has a large piston rod extending downwards from the piston to what is a second smaller-diameter piston.
The main piston carries the piston rings. The smaller piston is purely a mechanical guide, it runs within a small cylinder as a trunk guide and carries the gudgeon pin. Lubrication of the crosshead has advantages over the trunk piston as its lubricating oil is not subject to the heat of combustion: the oil is not contaminated by combustion soot particles, it does not break down owing to the heat and a thinner, less viscous oil may be used; the friction of both piston and crosshead may be only half of that for a trunk piston. Because of the additional weight of these pistons, they are not used for high-speed engines. Media related to Crosshead pistons at Wikimedia Commons A slipper piston is a piston for a petrol engine, reduced in size and weight as much as possible. In the extreme case, they are reduced to the piston crown, support for the piston rings, just enough of the piston skirt remaining to leave two lands so as to stop the piston rocking in the bore; the sides of the piston skirt around the gudgeon pin are reduced away from the cylinder wall.
The purpose is to reduce the reciprocating mass, thus making it easier to balan
Formula One is the highest class of single-seater auto racing sanctioned by the Fédération Internationale de l'Automobile and owned by the Formula One Group. The FIA Formula One World Championship has been one of the premier forms of racing around the world since its inaugural season in 1950; the word "formula" in the name refers to the set of rules to which all participants' cars must conform. A Formula One season consists of a series of races, known as Grands Prix, which take place worldwide on purpose-built circuits and on public roads; the results of each race are evaluated using a points system to determine two annual World Championships: one for drivers, the other for constructors. Drivers must hold valid Super Licences, the highest class of racing licence issued by the FIA; the races must run on tracks graded "1", the highest grade-rating issued by the FIA. Most events occur in rural locations on purpose-built tracks, but several events take place on city streets. Formula One cars are the fastest regulated road-course racing cars in the world, owing to high cornering speeds achieved through the generation of large amounts of aerodynamic downforce.
The cars underwent major changes in 2017, allowing wider front and rear wings, wider tyres, resulting in cornering forces closing in on 6.5g and top speeds of up to 375 km/h. As of 2019 the hybrid engines are limited in performance to a maximum of 15,000 rpm and the cars are dependent on electronics—although traction control and other driving aids have been banned since 2008—and on aerodynamics and tyres. While Europe is the sport's traditional base, the championship operates globally, with 11 of the 21 races in the 2018 season taking place outside Europe. With the annual cost of running a mid-tier team—designing and maintaining cars, transport—being US$120 million, Formula One has a significant economic and job-creation effect, its financial and political battles are reported, its high profile and popularity have created a major merchandising environment, which has resulted in large investments from sponsors and budgets. On 8 September 2016 Bloomberg reported that Liberty Media had agreed to buy Delta Topco, the company that controls Formula One, from private-equity firm CVC Capital Partners for $4.4 billion in cash and convertible debt.
On 23 January 2017 Liberty Media confirmed the completion of the acquisition for $8 billion. The Formula One series originated with the European Grand Prix Motor Racing of the 1930s; the formula is a set of rules. Formula One was a new formula agreed upon after World War II during 1946, with the first non-championship races being held that year. A number of Grand Prix racing organisations had laid out rules for a world championship before the war, but due to the suspension of racing during the conflict, the World Drivers' Championship was not formalised until 1947; the first world championship race was held at Silverstone, United Kingdom in 1950. A championship for constructors followed in 1958. National championships existed in the UK in the 1960s and 1970s. Non-championship Formula One events were held for many years, but due to the increasing cost of competition, the last of these occurred in 1983. On 26 November 2017, Formula One unveiled its new logo, following the 2017 season finale in Abu Dhabi during the Abu Dhabi Grand Prix at Yas Marina Circuit.
The new logo replaced F1's iconic'flying one', the sport's trademark since 1993. After a hiatus in European motor racing brought about by the outbreak of World War II in 1939, the first World Championship for Drivers was won by Italian Giuseppe Farina in his Alfa Romeo in 1950, narrowly defeating his Argentine teammate Juan Manuel Fangio. However, Fangio won the title in 1951, 1954, 1955, 1956, 1957, his streak interrupted by two-time champion Alberto Ascari of Ferrari. Although the UK's Stirling Moss was able to compete he was never able to win the world championship, is now considered to be the greatest driver never to have won the title. Fangio, however, is remembered for dominating Formula One's first decade and has long been considered the "Grand Master" of Formula One; this period featured teams managed by road car manufacturers Alfa Romeo, Mercedes-Benz, Maserati. The first seasons were run using pre-war cars like Alfa's 158, they were front-engined, with narrow tyres and 1.5-litre supercharged or 4.5-litre aspirated engines.
The 1952 and 1953 World Championships were run to Formula Two regulations, for smaller, less powerful cars, due to concerns over the paucity of Formula One cars available. When a new Formula One, for engines limited to 2.5 litres, was reinstated to the world championship for 1954, Mercedes-Benz introduced the advanced W196, which featured innovations such as desmodromic valves and fuel injection as well as enclosed streamlined bodywork. Mercedes drivers won the championship for two years, before the team withdrew from all motorsport in the wake of the 1955 Le Mans disaster. An era of British dominance was ushered in by Mike Hawthorn and Vanwall's championship wins in 1958, although Stirling Moss had been at the forefront of the sport without securing the world title. Between Hawthorn, Jim Clark, Jackie Stewart, John Surtees and Graham Hill, British drivers won nine Drivers' Championships and British teams won fourteen Constructors' Championsh
In everyday use and in kinematics, the speed of an object is the magnitude of its velocity. The average speed of an object in an interval of time is the distance travelled by the object divided by the duration of the interval. Speed has the dimensions of distance divided by time; the SI unit of speed is the metre per second, but the most common unit of speed in everyday usage is the kilometre per hour or, in the US and the UK, miles per hour. For air and marine travel the knot is used; the fastest possible speed at which energy or information can travel, according to special relativity, is the speed of light in a vacuum c = 299792458 metres per second. Matter can not quite reach the speed of light. In relativity physics, the concept of rapidity replaces the classical idea of speed. Italian physicist Galileo Galilei is credited with being the first to measure speed by considering the distance covered and the time it takes. Galileo defined speed as the distance covered per unit of time. In equation form, v = d t, where v is speed, d is distance, t is time.
A cyclist who covers 30 metres in a time of 2 seconds, for example, has a speed of 15 metres per second. Objects in motion have variations in speed. Speed at some instant, or assumed constant during a short period of time, is called instantaneous speed. By looking at a speedometer, one can read the instantaneous speed of a car at any instant. A car travelling at 50 km/h goes for less than one hour at a constant speed, but if it did go at that speed for a full hour, it would travel 50 km. If the vehicle continued at that speed for half an hour, it would cover half that distance. If it continued for only one minute, it would cover about 833 m. In mathematical terms, the instantaneous speed v is defined as the magnitude of the instantaneous velocity v, that is, the derivative of the position r with respect to time: v = | v | = | r ˙ | = | d r d t |. If s is the length of the path travelled until time t, the speed equals the time derivative of s: v = d s d t. In the special case where the velocity is constant, this can be simplified to v = s / t.
The average speed over a finite time interval is the total distance travelled divided by the time duration. Different from instantaneous speed, average speed is defined as the total distance covered divided by the time interval. For example, if a distance of 80 kilometres is driven in 1 hour, the average speed is 80 kilometres per hour. If 320 kilometres are travelled in 4 hours, the average speed is 80 kilometres per hour; when a distance in kilometres is divided by a time in hours, the result is in kilometres per hour. Average speed does not describe the speed variations that may have taken place during shorter time intervals, so average speed is quite different from a value of instantaneous speed. If the average speed and the time of travel are known, the distance travelled can be calculated by rearranging the definition to d = v ¯ t. Using this equation for an average speed of 80 kilometres per hour on a 4-hour trip, the distance covered is found to be 320 kilometres. Expressed in graphical language, the slope of a tangent line at any point of a distance-time graph is the instantaneous speed at this point, while the slope of a chord line of the same graph is the average speed during the time interval covered by the chord.
Average speed of an object is Vav = s÷t Linear speed is the distance travelled per unit of time, while tangential speed is the linear speed of something moving along a circular path. A point on the outside edge of a merry-go-round or turntable travels a greater distance in one complete rotation than a point nearer the center. Travelling a greater distance in the same time means a greater speed, so linear speed is greater on the outer edge of a rotating object than it is closer to the axis; this speed along a circular path is known as tangential speed because the direction of motion is tangent to the circumference of the circle. For circular motion, the terms linear speed and tangential speed are used interchangeably, both use units of m/s, km/h, others. Rotational speed involves the number of revolutions per unit of time. All parts of a rigid merry-
Monster Energy NASCAR Cup Series
The Monster Energy NASCAR Cup Series is the top racing series of the National Association for Stock Car Auto Racing. Since 2017, it has been named for its sponsor, Monster Energy, but has been known by other names in the past; the series began in 1949 as the Strictly Stock Division, from 1950 to 1970 it was known as the Grand National Division. In 1971, when the series began leasing its naming rights to the R. J. Reynolds Tobacco Company, it was referred to as the Winston Cup Series. A similar deal was made with Nextel in 2003, it became the Nextel Cup Series. Sprint acquired Nextel in 2005, in 2008 the series was renamed the Sprint Cup Series, which lasted until 2016. In December 2016, it was announced that Monster Energy would become the new title sponsor starting in 2017; the championship is determined by a points system, with points being awarded according to finish placement and number of laps led. The season is divided into two segments. After the first 26 races, 16 drivers, selected on the basis of wins during the first 26 races, are seeded based on their total number of wins.
They compete in the last ten races, where the difference in points is minimized. This is called the NASCAR playoffs; the series holds strong roots in the Southeastern United States, with half of the races in the 36-race season being held in that region. The current schedule includes tracks from around the United States. Regular season races were held in Canada, exhibition races were held in Japan and Australia; the Daytona 500, the most prestigious race, had a television audience of about 9.17 million U. S. viewers in 2019. Cup Series cars are unique in automobile racing; the engines are powerful enough to reach speeds of over 200 mph, but their weight coupled with a simple aerodynamic package make for poor handling. The bodies and chassis of the cars are regulated to ensure parity, electronics are traditionally spartan in nature. In 1949, NASCAR introduced the Strictly Stock division, after sanctioning Modified and Roadster division races in 1948. Eight races were run on the Daytona Beach beach/street course.
The first NASCAR "Strictly Stock" race was held at Charlotte Speedway on June 19, 1949. Jim Roper was declared the winner of that race after Glenn Dunaway was disqualified for having altered the rear springs on his car; the division was renamed "Grand National" for the 1950 season, reflecting NASCAR's intent to make the sport more professional and prestigious. It retained this name until 1971; the 1949 Strictly Stock season is regarded in NASCAR's record books as the first season of GN/Cup history. Martinsville Speedway is the only track on the 1949 schedule. Rather than having a fixed schedule of one race per weekend with most entrants appearing at every event, the Grand National schedule has included over sixty events in some years. There are two or three races on the same weekend and two races on the same day in different states. In the early years, most Grand National races were held on dirt-surfaced short oval tracks that ranged in lap length from under a quarter-mile to over a half-mile, or on dirt fairgrounds ovals ranging from a half-mile to a mile in lap length.
One hundred ninety-eight of the first 221 Grand National races were run on dirt tracks. Darlington Raceway, opened in 1950, was the first paved track on the circuit over one mile long. In 1959, when Daytona International Speedway was opened, the schedule still had more races on dirt racetracks than on paved ones. In the 1960s as superspeedways were built and old dirt tracks were paved, the number of races run on dirt tracks was reduced; the last NASCAR race on a dirt track was held on September 30, 1970 at the half-mile State Fairgrounds Speedway in Raleigh, North Carolina. Richard Petty won that race in a Plymouth, sold by Petty Enterprises to Don Robertson and rented back by Petty Enterprises for the race. Between 1971 and 2003, NASCAR's premier series was called the Winston Cup Series, it was sponsored by R. J. Reynolds Tobacco Company cigarette brand Winston. In 1971, the Public Health Cigarette Smoking Act banned television advertising of cigarettes; as a result, tobacco companies began to sponsor sporting events as a way to spend their excess advertising dollars and to circumvent the Public Health Cigarette Smoking Act's ban on television advertising.
RJR's sponsorship became more controversial in the wake of the 1998 Tobacco Industry Settlement that restricted avenues for tobacco advertising, including sports sponsorships. The changes that resulted from RJR's involvement in the series as well as from the reduction in schedule from 48 to 31 races per year established 1972 as the beginning of NASCAR's "modern era"; the season was made shorter, the points system was modified several times during the next four years. Races on dirt tracks and on oval tracks shorter than 250 miles were removed from the schedule, transferred to the short-lived NASCAR Grand National East Series. NASCAR's founder, Bill France Sr. turned over control of NASCAR to Bill France Jr.. In August 1974, France Jr. asked series publicist Bob Latford to design a points system with equal points being awarded for all races regardless of length or prize money. This system ensured that the top drivers would have to compete in all the races in order to become the series champion.
This system remained unchanged from 1975 until the Chase for the Championship was instituted in 2004. Since 1982, the Daytona 500 has been the first non-exhib
Top Fuel dragsters are the quickest accelerating racing cars in the world and the fastest sanctioned category of drag racers, with the fastest competitors reaching speeds of 335 miles per hour and finishing the 1,000 foot runs in 3.64 seconds. Because of the speeds, this class races to only a 1,000 foot distance, not the traditional 1,320 feet; the rule was changed in 2008 by the National Hot Rod Association following the fatal crash of Funny Car driver Scott Kalitta during a qualifying session at Old Bridge Township Raceway Park in Englishtown, New Jersey, USA. The shortening of the distance was used in the FIA at some tracks, as of 2012 is now the standard Top Fuel distance by the FIA; the International Hot Rod Association, which now sanctions Top Fuel in Australia, dropped the distance in September 2017 after Santo Rapisarda, a car owner who runs NHRA races in the United States, pushed for the change. A top fuel dragster accelerates from a standstill to 100 mph in as little as 0.8 seconds and can exceed 280 mph in just 660 feet.
This subjects the driver to an average acceleration of about 4.0 g0 over the duration of the race and with a peak of over 5.6 g0. Before their run, racers perform a burnout in order to clean and heat tires. Additionally, the burnout applies a layer of fresh rubber to the track surface, which improves traction during launch. At maximum throttle and RPM, the exhaust gases escaping from a dragster's open headers produce about 900–1,100 pounds-force of downforce; the massive airfoil over and behind the rear wheels produces much more, peaking at around 12,000 pounds-force when the car reaches a speed of about 330 mph. The engine of a Top Fuel dragster generates around 150 dB of sound at full throttle, enough to cause physical pain or permanent damage. A sound that intense is not just heard, but felt as pounding vibrations all over one's body, leading many to compare the experience of watching a Top Fuel dragster make a pass to'feeling as though the entire drag strip is being bombed.' Before a run, race announcers advise spectators to cover or plug their ears.
Ear plugs and earmuffs are handed out to fans at the entrance of a Top Fuel event. Dragsters are limited to a maximum wheelbase of 300 inches; the most prolific active driver in Top Fuel is Tony Schumacher, the most successful crew chief is Alan Johnson, the crew chief for 6 of Schumacher's championships, the back-to-back titles won by driver Gary Scelzi and was the crew chief for his brother Blaine for his entire professional career. The first female driver in the Top Fuel category is the most associated female in the drag racing world, Shirley Muldowney, who won three championships during her career. Since 2015, NHRA regulations limit the composition of the fuel to a maximum of 90% nitromethane. However, this mixture is not mandatory, less nitromethane may be used if desired. While nitromethane has a much lower energy density than either gasoline or methanol, an engine burning nitromethane can produce up to 2.3 times as much power as an engine burning gasoline. This is made possible by the fact that, in addition to fuel, an engine needs oxygen in order to generate force: 14.7 kg of air is required to burn one kilogram of gasoline, compared to only 1.7 kg of air for one kilogram of nitromethane, unlike gasoline has oxygen in its molecular composition.
For a given amount of air consumed, this means that an engine can burn 7.6 times more nitromethane than gasoline. Nitromethane has a high latent heat of vaporization, meaning that it will absorb substantial engine heat as it vaporizes, providing an invaluable cooling mechanism; the laminar flame speed and combustion temperature are higher than gasoline at 0.5 m/s and 2,400 °C respectively. Power output can be increased by using rich air-fuel mixtures; this helps prevent pre-ignition, a problem when using nitromethane. Due to the slow burn rate of nitromethane rich fuel mixtures are not ignited and some remaining nitromethane can escape from the exhaust pipe and ignite on contact with atmospheric oxygen, burning with a characteristic yellow flame. Additionally, after sufficient fuel has been combusted to consume all available oxygen, nitromethane can combust in the absence of atmospheric oxygen, producing hydrogen, which can be seen burning from the exhaust pipes at night as a bright white flame.
In a typical run the engine can consume between 12 US gallons and 22.75 US gallons of fuel during warmup, burnout and the quarter-mile run. Like many other motor sport formulas originating in the United States, NHRA-sanctioned drag racing favors heavy restrictions on engine configuration, sometimes to the detriment of technological development. In some regards, teams are required to use technologies that may be decades old, resulting in cars that may seem less advanced than the average family car. However, while some basic facets of engine configuration are restricted, other technologies, such as fuel injection, clutch operation and car materials and design, are under constant development. NHRA competition rules limit the engine displacement to 500 cubic inches. A 4.1875-inch bore with a 4.5-inch stroke are customary dimensions. Larger bores have been shown to weaken the cylinder block. Compression ra
A reciprocating engine often known as a piston engine, is a heat engine that uses one or more reciprocating pistons to convert pressure into a rotating motion. This article describes the common features of all types; the main types are: the internal combustion engine, used extensively in motor vehicles. Internal combustion engines are further classified in two ways: either a spark-ignition engine, where the spark plug initiates the combustion. There may be one or more pistons; each piston is inside a cylinder, into which a gas is introduced, either under pressure, or heated inside the cylinder either by ignition of a fuel air mixture or by contact with a hot heat exchanger in the cylinder. The hot gases expand; this position is known as the Bottom Dead Center, or where the piston forms the largest volume in the cylinder. The piston is returned to the cylinder top by a flywheel, the power from other pistons connected to the same shaft or by the same process acting on the other side of the piston.
This is. In most types the expanded or "exhausted" gases are removed from the cylinder by this stroke; the exception is the Stirling engine, which heats and cools the same sealed quantity of gas. The stroke is the distance between the TDC and the BDC, or the greatest distance that the piston can travel in one direction. In some designs the piston may be powered in both directions in the cylinder, in which case it is said to be double-acting. In most types, the linear movement of the piston is converted to a rotating movement via a connecting rod and a crankshaft or by a swashplate or other suitable mechanism. A flywheel is used to ensure smooth rotation or to store energy to carry the engine through an un-powered part of the cycle; the more cylinders a reciprocating engine has the more vibration-free it can operate. The power of a reciprocating engine is proportional to the volume of the combined pistons' displacement. A seal must be made between the sliding piston and the walls of the cylinder so that the high pressure gas above the piston does not leak past it and reduce the efficiency of the engine.
This seal is provided by one or more piston rings. These are rings made of a hard metal, are sprung into a circular groove in the piston head; the rings fit in the groove and press against the cylinder wall to form a seal, more when higher combustion pressure moves around to their inner surfaces. It is common to classify such engines by the number and alignment of cylinders and total volume of displacement of gas by the pistons moving in the cylinders measured in cubic centimetres or litres or. For example, for internal combustion engines and two-cylinder designs are common in smaller vehicles such as motorcycles, while automobiles have between four and eight, locomotives, ships may have a dozen cylinders or more. Cylinder capacities may range from 10 cm³ or less in model engines up to thousands of liters in ships' engines; the compression ratio affects the performance in most types of reciprocating engine. It is the ratio between the volume of the cylinder, when the piston is at the bottom of its stroke, the volume when the piston is at the top of its stroke.
The bore/stroke ratio is the ratio of the diameter of the piston, or "bore", to the length of travel within the cylinder, or "stroke". If this is around 1 the engine is said to be "square", if it is greater than 1, i.e. the bore is larger than the stroke, it is "oversquare". If it is less than 1, i.e. the stroke is larger than the bore, it is "undersquare". Cylinders may be aligned in line, in a V configuration, horizontally opposite each other, or radially around the crankshaft. Opposed-piston engines put two pistons working at opposite ends of the same cylinder and this has been extended into triangular arrangements such as the Napier Deltic; some designs have set the cylinders in motion around the shaft, such as the Rotary engine. In steam engines and internal combustion engines, valves are required to allow the entry and exit of gases at the correct times in the piston's cycle; these are worked by eccentrics or cranks driven by the shaft of the engine. Early designs used the D slide valve but this has been superseded by Piston valve or Poppet valve designs.
In steam engines the point in the piston cycle at which the steam inlet valve closes is called the cutoff and this can be controlled to adjust the torque supplied by the engine and improve efficiency. In some steam engines, the action of the valves can be replaced by an oscillating cylinder. Internal combustion engines operate through a sequence of strokes that admit and remove gases to and from the cylinder; these operations are repeated cyclically and an engine is said to be 2-stroke, 4-stroke or 6-stroke depending on the number of strokes it takes to complete a cycle. In some steam engines, the cylinders may be of varying size with the smallest bore cylinder working the highest pressure steam; this is fed through one or more larger bore cylinders successively, to extract power from the steam at lower pressures. These engines are called Compound engines. Aside from loo