How is the power of jet engines determined and how does it compare to the horsepower in piston engines?
548339
Horse power can be used for both it is a value given to the amount of energy needed to perform (x) amount of work per second.\n  I believe you are more interested in thrust, which is the forward propulsion of the jet engine.  \n  That would go more towards ft/lbs.  \n\nOne extra little known tid bit.  The super jet engines like on the C-5 military transport uses some water injection on take off.  This is what causes the dark exhaust you see. \n\nIf I remember correctly when water flashes to steam it has a 1:26 pressure expasion rate.  \nAs you can see this has a significant impact on the amount of thrust for the engine as well as a cooling effect.\n\nAnd of course the lift is all by design of the wing.  If you took the wings off of a plane it would never get off the ground...  \n\n    But it would make one fast car !!!
329007
horsepower is a standard unit of measure.
252267
The power comparison is about 8,000 hp(top fuel) to about 60,000hp(boeing) The fuel consumption comparison is apples to oranges. The boeing uses heavy jet propellant basically diesel fuel while the top fuel uses alchohol and nitro methane. it would be like comparing drinking water versus eggnog... What's the point?
340440
power is the amount of work done in unit time \nit is measured in Joules per second , dude
182772
The larger fan face/surface increases drag and balancing such a large fan becomes difficult, also the power generated by that much more fan disc area would not affect traction or thrust appreciably compared to the weight and complexity of the engine. There were concept jet fans with exposed six bladed propellers driven by more standard jet engines in the late 1970's but conventional turbine power quickly became just as officiant if not more and eclipsed the technology.\n\nKeep in mind, these power plants are designed to operating mounted to or buried within airliners. The master design of the aircraft dictates the size, thrust, weight and length of the engines.
155442
Not to be picky, but if you have a 383 engine in a GTO, somebody has done it a sever injustice.  383 is a Chrysler Corp. engine.  If you are meaning a 389 Tri-power, you have something around an advertised horsepower of 360hp with 431 ft. lb. torque.  The 4-bbl option produced 335hp with the same torque.
375519
Jet engines are tested for "bird ingestion" (using dead or anesthetized birds) as part of engine qualification (perhaps not for similar models).  The engines must remain intact.  Airplanes fly at very high elevations where the air is cleaner than at a power plant subject to wind storms.  A power plant can afford the extra weight of a filter system that would perhaps not fly.  An airliner once flew through the dust plume of a volcano (at night?) which snuffed out all (four?) engines at high elevation.  Luckily, the engines restarted after considerable effort on the part of the pilots.  Engine designers are concerned with the intake of fine dust into an engine that could perhaps get into bearings, etc.  Experience dictates adequate solutions to the problem.  Each engine design has a TBO (time between overhaul) that is lengthened with experience and complete dismantling of the engine allows evaluation of the effects of dust, etc. to maintain safety.
766096
I'm assuming you're talking about jet engines compared to stationary energy turbines.  I'm not sure what you're asking, so I'll just try to be general.  \n\n1st- Pressure and Velocity\nPressure and Velocity are related (in incompressible, inviscid flows -  pretty applicable to just get a feel for it) by Bernoulli's principal.  Basically it states that Stagnation Pressure (the pressure if you stopped the gas) is conserved along a streamline (the path air follows around or through an objet).  It is equal to the static pressure (pressure you feel outside) + 1/2 * Density * Speed ^2.  This boils down to if you do no work to the fluid, and allow a pressure drop, the gas will speed up (think water coming out of a hose).  \n\nNozzles\nNozzles work to reduce the area the fluid can flow through.  By shrinking the area, you force the fluid to move faster for the same amount of mass (rather then having 2 people walk through a door at the same time, they'd have to walk twice as fast in a single file line to get through).  The Nozzle increases the pressure in the chamber, forcing the gas to speed up at its exit - this is how the whole putting your thumb over the garden hose works, you force the flow to build up pressure behind your thumb so that it can escape at the same rate that it is being allowed to enter the hose.  \n\nThe converging nozzles on jet engines compress the flow to the speed of sound.  Rockets on the other hand have converging-diverging nozzles (they shrink then get bigger) which allows for a supersonic exhaust.  \n\nBypass Ratio /turbofan/turbojet\nThe bypass ratio refers to a turbofan engine.  A turbojet, turbofan, and turboprop all have a turbojet engine at the core, a turbo prop uses that engine to turn a propeller, a turbojet simply uses the engine to accelerate gases out of it, and a turbofan is kind of a hybrid of the two - it turns a 'fan' which also acts as a compressor.  The bypass ratio is the ratio of the airflow that only goes through the fan (and therefore bypasses the turbojet portiion of the engine) as compared to the amount of air that flows through the turbojet portion.  By bypassing the turbojet, the air moves more slowly - but the fan moves more of it so you get more efficent thrust, but a lower maximum speed.  The prop works ont eh same way, but moves even more air, with an even lower maximum speed, but a much higher efficiency.  \n\nTurbojet engine\nA turbojet engine runs on a Brayton cycle.  Basically you have 4 stages, compressor, combustion, turbine, exhaust.  As the air comes into the engine, it hits the compressor, which raises the pressure of the air, and allows it to stagnate (its hard to burn fuel when the air is moving).  Once the air is finished with the compressor, it enters into the combustion chamber, where it is mixed with fuel and burns.  This hotter high pressure air is then allowed to expand through a turbine (like a windmill or pinwheel) driving the turbine (the turbine is connected to the cmpressor through a shaft sot hat it drives the compressor).  The hot gases are then either put into an afterburner, where the air is heated up again, or not - and then forced through a nozzle to accelerate it (converting its pressure into speed).  The air leaving the engine is moving much faster then it was when it was taken in (its leaving at mach 1 - the speed of sound varies based on temperature, so its much faster then mach 1 of an airplane flying).  This is how it produces thrust.
582801
A turbojet engine is the simplest type of jet engine. It uses the high velocity of the exaust gases to generate thrust\n\nSites regardin Turbojet enhines and their working:\n\nhttp://en.wikipedia.org/wiki/Turbojet\n\nhttp://www.grc.nasa.gov/WWW/K-12//airplane/aturbj.html\n\nA TurboFan engine is the modified form of the turbojet engine. It has a fan in the front which is rotated with the help of a turbine connected to it. The hot exaust gases rotates the turbine which in turn rotates the Fan. The fan in turn pushes the air backwards and generates the major thrust. These type of engines are preffered in high speed passenger aircrafts as they can perform well in high altitudes and are quieter compared to turbojet aircrafts. They are also more fuel efficient than Turbojet aircrafts.\n\nSite regardin Turbofan Engine:\n\nhttp://www.grc.nasa.gov/WWW/K-12/airplane/Animation/turbtyp/etfr.html\n\nThe followin site contains description of diff types of jet engines:\n\nhttp://inventors.about.com/library/inventors/bljetenginetypes.htm\n\nHope this helps
908068
Gas turbines come in a variety of sizes from very small (a few hundred horsepower) to very large (in excess of 25,000 horsepower). \n\nYou need to do your homework and find out about the various manufacturers and the type of turbines they make. \n\nSome turbines are derived from air craft jet engines and other are heavy industrial types designed from the ground up for long term, continuous duty (a GE frame 5 or 7 would be examples of this type of turbine). There are others that are designed from the ground up but are not a robust as the heavy industrial type.\n\nYour application will help determine what manufacturers you need to consider. \n\nTry this site for starters.\n\nhttp://www.directindustry.com/tab/gas-turbine.html
179256
Steam turbines have several controlled nozzles which connect to the superheated steam source from the boiler and superheater.  The number of nozzles and steam flow rate through the nozzles can control the power output of the turbine.  The momentum of the steam gas hitting the turbine (in stages) as it expands spins the turbine creating shaft power.\n\nOne type of gas turbine is the exhaust side of a turbocharger.  Hot exhaust gas under pressure is pumped by the engine into the the outer ring of the turbine.  The gas is still expanding, and spins the turbine providing shaft power to drive the air compressor side.  \n\nThe type of gas turbine common to power plants and airplanes has a compressor section, combustion chamber, and expansion section.  The expansion and compression turbine sections have moving vanes and stationary vanes to direct the gases and extract the most work possible from the setup.  Atmospheric air is compressed by the compressor and fed at elevated pressure to the combustion chamber where fuel is injected and an ingnition source keeps the flame lit.  The exhaust spins the expansion section and exits through the rear of the engine.
834512
Torque is not the right question to ask in this problem!\nFirst define the generator output in terms of watts.\nAssume an efficiency of 0.8 for the generator and define the Input of the generator (In = Out / 0.8).\nThis is the output of your motor (assuming some diesel/petrol).\nTorque is expressed as N/m (force x radius) and is part of the electric generator specs.  See there to get the equivalence.\nUsually, the motor power is also 0.8 efficient, so the motor power should be W / (0.8*0.8) and that will give you the right ratio.
269888
Airplane uses gas turbines.\nA gas turbine, also called a combustion turbine, is a rotary engine that extracts energy from a flow of combustion gas. It has an upstream compressor coupled to a downstream turbine, and a combustion chamber in-between. (Gas turbine may also refer to just the turbine element.)\n\nEnergy is added to the gas stream in the combustor, where air is mixed with fuel and ignited. Combustion increases the temperature, velocity and volume of the gas flow. This is directed through a (nozzle) over the turbine's blades, spinning the turbine and powering the compressor.\n\nEnergy is extracted in the form of shaft power, compressed air and thrust, in any combination, and used to power aircraft, trains, ships, generators, and even tanks.\n\n\nTheory of operation\nGas turbines are described thermodynamically by the Brayton cycle, in which air is compressed isentropically, combustion occurs at constant pressure, and expansion over the turbine occurs isentropically back to the starting pressure.\n\nIn practise, friction and turbulence cause:\n\na) non-isentropic compression - for a given overall pressure ratio, the compressor delivery temperature is higher than ideal\n\nb) non-isentropic expansion - although the turbine temperature drop necessary to drive the compressor is unaffected, the associated pressure ratio is greater, which decreases the expansion available to provide useful work.\n\na) a pressure loss in the combustor - reduces the expansion available to provide useful work.\n\n\n\nAs with all cyclic heat engines, higher combustion temperature means greater efficiency. The limiting factor is the ability of the steel, ceramic, or other materials that make up the engine to withstand heat and pressure. Considerable engineering goes into keeping the turbine parts cool. Most turbines also try to recover exhaust heat, which otherwise is wasted energy. Recuperators are heat exchangers that pass exhaust heat to the compressed air, prior to combustion. Combined cycle designs pass waste heat to steam turbine systems. And combined heat and power (co-generation) uses waste heat for hot water production.\n\nMechanically, gas turbines can be considerably less complex than internal combustion piston engines. Simple turbines might have one moving part: the shaft/compressor/turbine/alternator-rotor assembly (see image above), not counting the fuel system.\n\nMore sophisticated turbines may have multiple shafts (spools), hundreds of turbine blades, movable stator blades, and a vast system of complex piping, combustors and heat exchangers.\n\nAs a general rule, the smaller the engine the faster the shaft/s rotate, to maintain tip speed: Jet engines operate around 10,000 rpm and micro turbines around 100,000 rpm.\n\nThrust bearings and journal bearings are a critical part of design. Traditionally, they have been hydrodynamic oil bearings, or oil-cooled ball bearings. This is giving way to hydrodynamic foil bearings, which have become common place in micro turbines and APU’s (auxiliary power units.)\n\nAuxiliary power units (APUs) are small gas turbines designed for auxiliary power of larger machines, usually aircraft. They are well suited for supplying compressed air for aircraft ventilation (with an appropriate compressor design), start-up power for larger jet engines, and electrical and hydraulic power. (These are not to be confused with the auxiliary propulsion units, also abbreviated APUs, aboard the gas-turbine-powered Oliver Hazard Perry-class guided-missile frigates. The Perrys' APUs are large electric motors that provide maneuvering help in close waters, or emergency backup if the gas turbines are not working.)
614194
A turbo charger forces more fuel/air into the cylinders, so there's more fuel to explode, so there's more power.\nIt works by spinning an impeller VERY fast (20,000 rpm), powered off the exhaust gases.\nA supercharger is similar, but it is powered directly from the engine.
839893
"turbo" used in normal piston driven engines uses the exhaust gasses energy to drive a (typically) radial turbine that is connected to a compressor that compresses the intake air. \n\nThe increased amount of air (mainly the oxigen in interesting) allows to add more fule to the mix and create a larger explosion in the cilinder yielding more power.\n\nThe air can optionally be cooled using an "intercooler" (air-to-air heat exchanger)\n\nFor diesel powered engines the result is an increase in power of the engine and an improvement of the fuel economy. For gasoline powered engines the results are an increased power, but the fuel economy might go either way.
1131605
Most turbine engines are "free turbine" design, which means that the N1 turbine and the N2 turbine are not physically connected on the same shaft.  (when I say turbine engine, this can be applicable to a turboshaft, turboprop or some jet engines, the principle is all the same).\n\nN1 is the Gas Producer Turbine, whose main function is to turn the compressor, which supplies the engine with air.  The N2 is the power turbine, which is connected through a drive train to a propeller or rotor and carries the load.  These two turbines are both directly downstream from the hot section of the engine.\n\nIf the engine was not governed, rpm changes that occur to the N1 turbine would occur shortly thereafter to the N2.  This would be accomplished by adding more fuel, which would turn the N1 and compressor faster, producing more combustible air, creating a hotter fire, which would cause the N2 to increase in speed.  Free turbine engines, however, are governed to a constant N2 speed.  N2 rpm appears to remain constant.  Small, imperceptible droops in rpm are actually constantly occurring in response to increased load from the prop or rotor.  The governor automatically increases fuel flow, which shows as an increase of N1 and internal temperature, without any obvious change in N2.  Thus, in actual practice, N1 increases with load, (or altitude) and N2 stays the same.\n\nIn a fixed turbine engine, which is used in some airplanes and some older helicopters, the N1 and N2 turbines are connected by the same shaft and turn as one.  Larger fluctuations in rpm and lag times to spool the engine back up after drooping have made this style less attractive to aircraft designers than the free turbine.
958842
Horsepower is defined as work done over time. The exact definition of one horsepower is 33,000 lb.ft./minute. Put another way, if you were to lift 33,000 pounds one foot over a period of one minute, you would have been working at the rate of one horsepower. In this case, you'd have expended one horsepower-minute of energy. \n\nBrake horsepower (bhp) is the measure of an engine's horsepower without the loss in power caused by the gearbox, generator, differential, water pump and other auxiliaries. Thus the prefix "brake" refers to where the power is measured: at the engine's output shaft, as on an engine dynamometer. The actual horsepower delivered to the driving wheels is less.