Diesel engines work by compressing only the air. This increases the air temperature inside the cylinder to such a degree that it ignites atomised diesel fuel that is injected into the combustion chamber. This contrasts with spark-ignition engines such as an engine or gas engine. In diesel engines, glow plugs may be used to aid starting in cold weather, or when the engine uses a lower compression-ratio, the original diesel engine operates on the constant pressure cycle of gradual combustion and produces no audible knock. Low-speed diesel engines can have an efficiency that exceeds 50%. Diesel engines may be designed as either two-stroke or four-stroke cycles and they were originally used as a more efficient replacement for stationary steam engines. Since the 1910s they have used in submarines and ships. Use in locomotives, heavy equipment and electricity generation plants followed later, in the 1930s, they slowly began to be used in a few automobiles. Since the 1970s, the use of engines in larger on-road and off-road vehicles in the US increased.
According to the British Society of Motor Manufacturing and Traders, the EU average for diesel cars accounts for 50% of the total sold, including 70% in France and 38% in the UK. The worlds largest diesel engine is currently a Wärtsilä-Sulzer RTA96-C Common Rail marine diesel, the definition of a Diesel engine to many has become an engine that uses compression ignition. To some it may be an engine that uses heavy fuel oil, to others an engine that does not use spark ignition. However the original cycle proposed by Rudolf Diesel in 1892 was a constant temperature cycle which would require higher compression than what is needed for compression ignition. Diesels idea was to compress the air so tightly that the temperature of the air would exceed that of combustion, to make this more clear, let it be assumed that the subsequent combustion shall take place at a temperature of 700°. Then in that case the pressure must be sixty-four atmospheres, or for 800° centigrade the pressure must be ninety atmospheres.
In years Diesel realized his original cycle would not work, Diesel describes the cycle in his 1895 patent application. Notice that there is no longer a mention of compression temperatures exceeding the temperature of combustion, now all that is mentioned is the compression must be high enough for ignition. In 1806 Claude and Nicéphore Niépce developed the first known internal combustion engine, the Pyréolophore fuel system used a blast of air provided by a bellows to atomize Lycopodium
Lobe pumps are used in a variety of industries including pulp and paper, food, beverage and biotechnology. Rotary pumps can handle solids, pastes, and a variety of liquids, if wetted, they offer self-priming performance. A gentle pumping action minimizes product degradation and they offer continuous and intermittent reversible flows and can operate dry for brief periods of time. Flow is relatively independent of changes in pressure, too, so output is relatively constant. Lobe pumps are similar to external gear pumps in operation in that flows around the interior of the casing. Unlike external gear pumps, the lobes do not make contact, Lobe contact is prevented by external timing gears located in the gearbox. Pump shaft support bearings are located in the gearbox, and since the bearings are out of the liquid, pressure is limited by bearing location. As the lobes come out of mesh, they create expanding volume on the side of the pump. Liquid flows into the cavity and is trapped by the lobes as they rotate, liquid travels around the interior of the casing in the pockets between the lobes and the casing—it does not pass between the lobes.
Finally, the meshing of the lobes forces liquid through the port under pressure. Lobe pumps are used in food applications because they handle solids without damaging the product. Particle size pumped can be larger in lobe pumps than in other positive displacement types. Since the lobes do not make contact, and clearances are not as close as in other Positive displacement pumps, loading characteristics are not as good as other designs, and suction ability is low. High-viscosity liquids require reduced speeds to achieve satisfactory performance, reductions of 25% of rated speed and lower are common with high-viscosity liquids. Roots blower PumpSchool. com Lobe Pump entry
Roots Blower Company
The Roots Blower Company was an American engineering company based in Connersville, Indiana. It was founded in 1859 by the inventors Philander Higley Roots and it is notable for the Roots blower, a type of pump. Today, Roots blowers are mainly used as air pumps in superchargers for internal combustion engines, the Roots brothers chose Connersville, Indiana as the Whitewater Canal provided a convenient 11 foot drop suitable for an undershot mill wheel. When this proved insufficiently powerful, Philander Roots built an efficient water motor to exploit the power source. However, the lobe impellers were made of wood, which warped and caused the motor to jam when used under water. As the brothers studied the problem on dry land, one of them rotated a shaft, causing the impellers to spin in the air and this attracted the attention of the superintendent of an iron foundry, who observed to Roots that it could be used to help melt iron. Roots followed up the idea by designing the Roots blower, now the product of the plant.
The foundry superintendent was given the role of foreman at Roots Blower. The Roots brothers patented the Roots Blower in 1860, in 1869 they were granted a patent by the International Patent Office, London for the invention of improvements in rotary blowing machines. In 1875, Roots exhibited a blower at the St Petersburg Exhibition, Thwaites, in 1885 Edgar Dwight Johnston joined the firm of 30 people, he became vice president in 1889 and president in 1898, remaining so until at least 1931. At that time the firm employed about 225 people, in 1900, Gottlieb Daimler patented a Roots supercharger for a cars internal combustion engine. In 1931, Roots Blower Company and Connersville Blower Company were bought by the International Derrick, the same year, the company began production of centrifugal compressors. During the Second World War, the company made screw compressors for U. S. Navy submarines, from 1944, Roots became a product brand of Dresser Industries, now part of. The Roots product line includes a range of blowers.
Francis Roots was born in Oxford, Ohio on 28 October 1824 to Alanson Roots and he married Esther E. Pumphrey on 8 October 1850. He died in Connersville on 25 October 1889 and his brother Philander died in Connersville in 1879. IN-3, P. H. & F. M. Roots Company, Eastern Avenue, Fayette County, IN,35 photos,6 measured drawings,11 data pages,2 photo caption pages
It consists of a series of short cylindrical rollers held together by side links. It is driven by a wheel called a sprocket. It is a simple and efficient means of power transmission, though Hans Renold is credited with inventing the roller chain in 1880, sketches by Leonardo da Vinci in the 16th century show a chain with a roller bearing. There are actually two types of links alternating in the roller chain. The first type is inner links, having two inner plates held together by two sleeves or bushings upon which rotate two rollers. Inner links alternate with the type, the outer links. This has the advantage of removing one step in assembly of the chain, the roller chain design reduces friction compared to simpler designs, resulting in higher efficiency and less wear. This problem was solved by the development of bushed chains. This distributed the wear over an area, however the teeth of the sprockets still wore more rapidly than is desirable. There is even very low friction, as long as the chain is sufficiently lubricated, clean, lubrication of roller chains is of primary importance for efficient operation as well as correct tensioning.
Many driving chains operate in environments, and thus the wearing surfaces are safe from precipitation and airborne grit. Some roller chains are designed to have built into the space between the outside link plate and the inside roller link plates. Chain manufacturers began to include this feature in 1971 after the application was invented by Joseph Montano while working for Whitney Chain of Hartford, Connecticut. O-rings were included as a way to improve lubrication to the links of power transmission chains and these rubber fixtures form a barrier that holds factory applied lubricating grease inside of the pin and bushing wear areas. Further, the rubber o-rings prevent dirt and other contaminants entering the inside of the chain linkages. There are many chains that have to operate in dirty conditions, examples include chains on farm equipment and chain saws. Chains operating at speeds comparable to those on motorcycles should be used in conjunction with an oil bath. For modern motorcycles this is not possible, and most motorcycle chains run unprotected, motorcycle chains tend to wear very quickly relative to other applications
Drag racing is a type of motor racing in which automobiles or motorcycles compete, usually two at a time, to be first to cross a set finish line. Electronic timing and speed sensing systems have used to record race results since the 1960s. This article covers the legal sport, before each race, each driver is allowed to perform a burnout, which heats the driving tires and lays rubber down at the beginning of the track, improving traction. Each driver lines up at the starting line, current NHRA trees, for example, feature one blue light, three amber, one green, and one red. When the first light beam is broken by a front tire, the vehicle is pre-staged. When the second beam is broken, the vehicle is staged. Vehicles may leave the beam, but must remain in the stage beam until the race starts. Once one competitor is staged, their opponent has a set amount of time to stage or they will be disqualified, indicated by a red light on the tree. Otherwise, once both drivers are staged, the system chooses a short delay at random, starts the race, the light sequence at this point varies slightly.
For example, in NHRA Professional classes, three amber lights on the tree flash simultaneously, followed 0.4 seconds by a green light. In NHRA Sportsman classes, the amber lights illuminate in sequence from top to bottom,0.5 seconds apart, if a vehicle leaves the start line before the green light illuminates, the red light for that lane illuminates instead, and the driver is disqualified. As a red light infraction is only assessed to the driver with the worse infraction, even if both drivers leave early, the green light is automatically lit for the driver that left last, and they still may win the pass. Several measurements are taken for each race, reaction time, elapsed time, reaction time is the period from the green light illuminating to the vehicle leaving the starting line. Elapsed time is the period from the leaving the starting line to crossing the finish line. Speed is measured through a speed trap covering the final 66 feet to the finish line, except where a breakout rule is in place, the winner is the first vehicle to cross the finish line, and therefore the driver with the lowest combined reaction time and elapsed time.
Because these times are measured separately, a driver with an elapsed time can actually win if that drivers advantage in reaction time exceeds the elapsed time difference. In heads-up racing, this is known as a holeshot win, in categories where a breakout rule is in effect, if a competitor is faster than his or her predetermined time, that competitor loses. If both competitors are faster than their predetermined times, the competitor who breaks out by less time wins, regardless, a red light foul is worse than a breakout, except in Junior Dragster where exceeding the absolute limit is a cause for disqualification
A gear or cogwheel is a rotating machine part having cut teeth, or cogs, which mesh with another toothed part to transmit torque. Geared devices can change the speed and direction of a power source, Gears almost always produce a change in torque, creating a mechanical advantage, through their gear ratio, and thus may be considered a simple machine. The teeth on the two meshing gears all have the same shape, two or more meshing gears, working in a sequence, are called a gear train or a transmission. A gear can mesh with a linear toothed part, called a rack, the gears in a transmission are analogous to the wheels in a crossed, belt pulley system. An advantage of gears is that the teeth of a gear prevent slippage, in transmissions with multiple gear ratios—such as bicycles and cars—the term gear as in first gear refers to a gear ratio rather than an actual physical gear. The term describes similar devices, even when the ratio is continuous rather than discrete, or when the device does not actually contain gears.
Early examples of gears date from the 4th century BC in China, examples of further development include, Ma Jun used gears as part of a south-pointing chariot. The Antikythera mechanism is an example of an early and intricate geared device. Its time of construction is now estimated between 150 and 100 BC, the water-powered grain-mill, the water-powered saw mill, fulling mill, and other applications of watermill often used gears. The first mechanical clocks were built in AD725, the 1386 Salisbury cathedral clock may be the worlds oldest working mechanical clock. The definite ratio that teeth give gears provides an advantage over other drives in precision machines such as watches that depend upon an exact velocity ratio, an external gear is one with the teeth formed on the outer surface of a cylinder or cone. Conversely, a gear is one with the teeth formed on the inner surface of a cylinder or cone. For bevel gears, a gear is one with the pitch angle exceeding 90 degrees. Internal gears do not cause output shaft direction reversal, spur gears or straight-cut gears are the simplest type of gear.
They consist of a cylinder or disk with teeth projecting radially, though the teeth are not straight-sided, the edge of each tooth is straight and aligned parallel to the axis of rotation. These gears mesh together correctly only if fitted to parallel shafts, No axial thrust is created by the tooth loads. Spur gears are excellent at moderate speeds but tend to be noisy at high speeds, helical or dry fixed gears offer a refinement over spur gears. The leading edges of the teeth are not parallel to the axis of rotation, since the gear is curved, this angling makes the tooth shape a segment of a helix
Detroit Diesel Series 71
This feature assisted in keeping down the overall cost of these large engines by maintaining parts commonality with the smaller models. The inline six-cylinder 71 series engine was introduced as the flagship product of the Detroit Diesel Engine Division of General Motors in 1938. The V-type first appeared in 1957, the 71 in the model series designation refers to the displacement per cylinder in cubic inches. Bore and stroke is the same to all units, at 4.25 x 5.0 inches. Inline models were famously symmetrical, meaning that blower, water manifold, starter, a number of models could run either clock-wise or counter clock-wise, called Right Hand or Left Hand engines. The less common Left Hand engines were used in buses. The engine exhausts through pushrod-operated poppet valves in the cylinder head, unit injection is employed, one injector per cylinder, with no high fuel pressure outside of the injector body. The injectors are cycled from the same responsible for opening the exhaust valves. As a two-stroke diesel engine that does not use crankcase aspiration cannot naturally aspirate combustion air and they can be known as Naturally Aspirated versions with an N suffix.
Later high-performance versions were available with turbochargers, and turbochargers with intercooling, the 71 Series went off of the market in the summer of 1995, and the Four Stroke Detroit Diesel Engine was introduced as a replacement. The most popular incarnations of the series 71 engine as used for vehicle applications included the inline 6-71, the V-block 6V-71. The 71 series is popular in marine applications, not only as a propulsion engine in small craft but as auxiliary power to drive generators, winches. The Motor Lifeboat CG36500 featured in The Finest Hours movie had a used Detroit 4-71 added AFTER the SS Pendleton rescue and her original engine was a Sterling Petrel 6 cylinder gas engine, which suffered fuel starvation when the boat rolled violently due to the carburetor float getting hung up. Over the years, the 71 series has enjoyed a reputation for dependability, due to their ubiquity and operating characteristics, inline models acquired a variety of nicknames from those who used and serviced them.
Most common were Screaming Jimmy or Rocky Mountain Humming Bird, which referred to the engines sound at full throttle. The V12 has been called the Buzzin Dozen due to the higher RPM needed for it to produce power and what sound it makes when the exhaust brake is on. The inline 6-71 was adapted to British requirements as the plant for Canadian built Valentine tanks where it was known as the GMC6004. The 6046 Diesel was a twin engine setup used by US, the eight engines produced a total of 1600BHP
GM Ecotec engine
The GM Ecotec engine, known by its codename L850, is a family of all-aluminium inline-four engines, displacing between 2.0 and 2.5 litres. While these engines were based on the GM Family II engine and this engine family replaced the GM Family II engine, the GM122 engine, the Saab H engine, and the Quad 4 engine. It is manufactured in multiple locations, to include Spring Hill Manufacturing, in Spring Hill, the Ecotec name was adopted in 2000 for the new generation of Family II engines. The name was used for the Opel GM Family II engine, Family 1. GM intends this new Ecotec to become its global 4-cylinder, the Ecotec engine is a DOHC 4-valve design with an forged steel block and head, designed for displacements from 1.8 to 2.4 L. Much of the development work on this project was carried out by Lotus Engineering, the engine uses aluminum pistons and cast iron cylinder liners. Vibration is reduced with twin balance shafts, the first engine in the Ecotec Gen I line-up was Ecotec 2.2 L61, introduced in 2000.
The current Ecotec line is manufactured in Tonawanda, New York and this engine is known as B207 when used by Saab and Z20NET by Opel for use in the Vectra C and Signum. LK9 is a turbocharged 2.0 L—1,998 cc —version of the L850 series Ecotec utilizing an all-new reinforced sand cast aluminum cylinder head, the exhaust valves are liquid sodium-cooled. All vehicles using this engine feature Saabs Trionic 8 engine management system as well as a valve train. The timing chain and timing gears are new, along with Saabs Direct Ignition system, the reinforcements, intercooling, dual overhead camshaft, and such were developed by GM Powertrain Sweden. It features an 86 millimetres bore and stroke and a 9.5,1 compression ratio, maximum power is 210 horsepower at 5300 rpm and 221 ft·lb of torque at 2500 rpm. The LSJ shares many of its components with the LK9 such as, piston cooling jets, oil cooler, connecting rods, oil pan, sodium-filled exhaust valves and cylinder head. It is rated at 205 hp at 5600 rpm and 200 ft·lb at 4400 rpm with a ratio of 9.5,1.
With the end of the Chevy Cobalt S/C SS and Saturn Ion Red Line, in late 2005 Brammo Motorsports struck a deal with GM for the Supercharged 2.0 L Ecotec for their Ariel Atom. The engine came in various ratings from 205 hp to 300 hp, the LSJ was on the Wards 10 Best Engines list for 2006. This engine is used in, This engine is known as a Z22SE in other countries such as The United Kingdom. The basic Family II architecture was substantially re-engineered in 2000 to become the Ecotec Gen I, unlike its notably harsh predecessor, the engine was designed for smoothness
A gas meter is a specialized flow meter, used to measure the volume of fuel gases such as natural gas and propane. Gas meters are used at residential and industrial buildings that consume fuel gas supplied by a gas utility, gases are more difficult to measure than liquids, as measured volumes are highly affected by temperature and pressure. Gas meters measure a volume, regardless of the pressurized quantity or quality of the gas flowing through the meter. Temperature and heating value compensation must be made to measure actual amount and these are the most common type of gas meter, seen in almost all residential and small commercial installations. Within the meter there are two or more chambers formed by movable diaphragms, with the gas flow directed by internal valves, the chambers alternately fill and expel gas, producing a near continuous flow through the meter. As the diaphragms expand and contract, levers connected to cranks convert the motion of the diaphragms into rotary motion of a crank shaft which serves as the primary flow element.
This shaft can drive an odometer-like counter mechanism or it can produce electrical pulses for a flow computer, diaphragm gas meters are positive displacement meters. Rotary meters are highly machined precision instruments capable of handling higher volumes and pressures than diaphragm meters, within the meter, two figure 8 shaped lobes, the rotors, spin in precise alignment. With each turn, they move a specific quantity of gas through the meter, the operating principle is similar to that of a Roots blower. The rotational movement of the crank shaft serves as a primary flow element, turbine gas meters infer gas volume by determining the speed of the gas moving through the meter. Because the volume of gas is inferred by the flow, it is important that flow conditions are good, a small internal turbine measures the speed of the gas, which is transmitted mechanically to a mechanical or electronic counter. These meters do not impede the flow of gas, but are limited at measuring lower flow rates, an orifice gas meter consists of a straight length of pipe inside which a precisely known orifice creates a pressure drop, thereby affecting flow.
Orifice meters are a type of meter, all of which infer the rate of gas flow by measuring the pressure difference across a deliberately designed and installed flow disturbance. The gas static pressure, density and temperature must be measured or known in addition to the pressure for the meter to accurately measure the fluid. Orifice meters often do not handle a range of flow rates. They are however accepted and understood in industrial applications since they are easy to field-service and have no moving parts, ultrasonic flow meters are more complex than meters that are purely mechanical, as they require significant signal processing and computation capabilities. Ultrasonic meters measure the speed of gas movement by measuring the speed at which sound travels in the medium within the pipe. The most elaborate types of flow meters average speed of sound over multiple paths in the pipe
Hot rods are typically old, classic American cars with large engines modified for linear speed. The origin of the hot rod is unclear. Some automotive historians say that the term originated with stolen vehicles being refitted with another engine, in the early days of automobile manufacturing there was no identical matching transmission, body frame, and engine numbers. It was possible to change engines and repaint the car or truck and in turn it into a different vehicle. The term hot was equivalent to being stolen, the term rod was equivalent to any motorized vehicle. Another possible origin includes replacement of the camshaft with a new version, roadsters were the cars of choice because they were light, easy to modify, and inexpensive. The term became commonplace in the 1930s or 1940s as the name of a car that had been hopped up by modifying the engine for higher performance, a term common in the early days was gow job. This has fallen into disuse except with historians, the term has broadened to apply to other items that are modified for a particular purpose, such as hot-rodded amplifier.
The activity increased in popularity after World War II, particularly in California, many cars were prepared by bootleggers in response to Prohibition to enable them to avoid revenue agents, some police vehicles were modified in response. The first hot rods were old cars, modified to reduce weight, speedster was a common name for the modified car. Wheels and tires were changed for improved traction and handling, Hot rod was sometimes a term used in the 1950s as a derogatory term for any car that did not fit into the mainstream. Hot rodders modifications were considered to improve the appearance as well, engine swaps often involved fitting the Ford flathead engine, or flatty, in a different chassis, the 60 horse in a Jeep was a popular choice in the 40s. In the 1950s, the block was often fitted with crankshafts of up to 4.125 in stroke. In addition, rodders in the 1950s routinely bored them out by 0.1875 in, due to the tendency of blocks to crack as a result of overheating, a perennial problem, in the 50s and 60s, the flatty was supplanted by the early hemi.
By the 1970s, the small-block Chevy was the most common option, and since the 80s, after World War II there were many small military airports throughout the country that were either abandoned or rarely used that allowed hot rodders across the country to race on marked courses. Originally drag racing had tracks as long as one mile or more, as hot rodding became more popular in the 1950s, magazines and associations catering to hot rodders were started. These were led by Honk. and Car Craft, as some hot rodders raced on the street, a need arose for an organization to promote safety, and to provide venues for safe racing. Hot rodders including Wally Parks created the National Hot Rod Association to bring racing off the streets and they created rules based on safety and entertainment, and allowed Hot Rodders of any caliber the ability to race
Ideal gas law
The ideal gas law is the equation of state of a hypothetical ideal gas. It is an approximation of the behavior of many gases under many conditions. It was first stated by Émile Clapeyron in 1834 as a combination of the empirical Boyles law, Charless law and it can be derived microscopically from kinetic theory, as was achieved by August Krönig in 1856 and Rudolf Clausius in 1857. The state of an amount of gas is determined by its pressure, the modern form of the equation relates these simply in two main forms. The temperature used in the equation of state is an absolute temperature, in SI units, P is measured in pascals, V is measured in cubic metres, n is measured in moles, and T in kelvins. R has the value 8.314 J/ ≈2 cal/, how much gas is present could be specified by giving the mass instead of the chemical amount of gas. Therefore, a form of the ideal gas law may be useful. The chemical amount is equal to the mass of the gas divided by the molar mass. By replacing n with m/M and subsequently introducing density ρ = m/V, we get, defining the specific gas constant Rspecific as the ratio R/M, P = ρ R specific T.
This form of the gas law is very useful because it links pressure, density. Alternatively, the law may be written in terms of the specific volume v and it is common, especially in engineering applications, to represent the specific gas constant by the symbol R. In such cases, the gas constant is usually given a different symbol such as R ¯ to distinguish it. In any case, the context and/or units of the gas constant should make it clear as to whether the universal or specific gas constant is being referred to. KB =R/NA The number density contrasts to the formulation, which uses n, the number of moles and V. This relation implies that R = NAkB, where NA is Avogadros constant, in extreme conditions the principles of statistical mechanics may break down as some of the assumptions relating a real life example to an ideal gas become untrue. In SI units, P is measured in pascals, V in cubic metres, Y is a dimensionless number, KB has the value 1. 38·10−23 J/K in SI units. According to the assumptions of the theory of gases, we assumed that there are no inter molecular attractions between the molecules of an ideal gas its potential energy is zero.
Hence, all the energy possessed by the gas is kinetic energy, E =32 R T This is the kinetic energy of one mole of a gas
A heat exchanger is a device used to transfer heat between a solid object and a fluid, or between two or more fluids. The fluids may be separated by a wall to prevent mixing or they may be in direct contact. They are widely used in heating, air conditioning, power stations, chemical plants, petrochemical plants, petroleum refineries, natural-gas processing. Another example is the heat sink, which is a heat exchanger that transfers the heat generated by an electronic or a mechanical device to a fluid medium. There are three classifications of heat exchangers according to their flow arrangement. In parallel-flow heat exchangers, the two enter the exchanger at the same end, and travel in parallel to one another to the other side. In counter-flow heat exchangers the fluids enter the exchanger from opposite ends, in a cross-flow heat exchanger, the fluids travel roughly perpendicular to one another through the exchanger. For efficiency, heat exchangers are designed to maximize the area of the wall between the two fluids, while minimizing resistance to fluid flow through the exchanger.
The exchangers performance can be affected by the addition of fins or corrugations in one or both directions, which increase surface area and may channel fluid flow or induce turbulence. The driving temperature across the heat transfer surface varies with position, in most simple systems this is the log mean temperature difference. Sometimes direct knowledge of the LMTD is not available and the NTU method is used, double pipe heat exchangers are the simplest exchangers used in industries. On one hand, these heat exchangers are cheap for both design and maintenance, making them a choice for small industries. On the other hand, their low efficiency coupled with the space occupied in large scales, has led modern industries to use more efficient heat exchangers like shell. However, since double pipe heat exchangers are simple, they are used to teach heat exchanger design basics to students as the rules for all heat exchangers are the same. Shell and tube heat exchangers consist of series of tubes, One set of these tubes contains the fluid that must be either heated or cooled.
The second fluid runs over the tubes that are being heated or cooled so that it can provide the heat or absorb the heat required. A set of tubes is called the tube bundle and can be made up of types of tubes, longitudinally finned. Shell and tube heat exchangers are used for high-pressure applications