thrust
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(thrŭst) 
v., thrust, thrust·ing, thrusts. v.tr.
thrustful thrust'ful adj.
v., thrust, thrust·ing, thrusts. v.tr.
- To push or drive quickly and forcibly. See synonyms at push.
- To issue or extend: poplars thrusting their branches upward; thrust out his finger.
- To force into a specified condition or situation: She thrust herself through the crowd. He was thrust into a position of awesome responsibility.
- To include or interpolate improperly.
- To force on an unwilling or improper recipient: "Some have greatness thrust upon them" (Shakespeare).
- Archaic. To stab; pierce.
- To shove something into or at something else; push.
- To pierce or stab with or as if with a pointed weapon.
- To force one's way.
- A forceful shove or push.
- A driving force or pressure.
- The forward-directed force developed in a jet or rocket engine as a reaction to the high-velocity rearward ejection of exhaust gases.
- A piercing movement made with or as if with a pointed weapon; a stab.
- The essence; the point: The whole thrust of the project was to make money.
- Architecture. Outward or lateral stress in a structure, as that exerted by an arch or vault.
- An attack or assault, especially by an armed force.
[Middle English thrusten, from Old Norse thrȳsta.]
thruster thrust'er n.thrustful thrust'ful adj.
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thrust
The force that propels an aerospace vehicle or marine craft. Thrust is a vector quantity. Its magnitude is usually given in newtons (N) in International System (SI) units or pounds-force (lbf) in U.S. Customary Units. A newton is defined as 1 kilogram mass times an acceleration of 1 meter per second squared. One newton equals approximately 0.2248 lbf. See also Force; Units of measurement.
The thrust power of a vehicle is the thrust times the velocity of the vehicle. It is expressed in joules (J) per second or watts (W) in SI units. In U.S. Customary Units thrust power is expressed in foot-pounds per second, which can be converted to horsepower by dividing by 550. See also Jet propulsion; Power; Ramjet; Reciprocating aircraft engine; Rocket; Turbojet.
Roget's Thesaurus:
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thrust
verb
- To force to move or advance with or as if with blows or pressure: drive, propel, push, ram, shove. See move/halt.
- To cause to penetrate with force: dig, drive, plunge, ram, run, sink, stab, stick. See put in/take out.
- To cause to stick out: poke, push, shove. See convex/concave.
noun
- An act or instance of using force so as to propel ahead: butt1, push, shove. See push/pull.
- The thread or current of thought uniting or occurring in all the elements of a text or discourse: aim, burden2, drift, intent, meaning, purport, substance, tendency, tenor. See meaning.
Antonyms by Answers.com:
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thrust
n
Definition: forward movement
Antonyms: pull
v
Definition: push hard
Antonyms: pull
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A movement causing the formation of a reverse fault of a very low angle. The thrust plane is the low-angle fault face over which movement occurs.
1. The amount of push or force exerted by or on a structure.
2. In an arch, the resultant force normal to any cross section of the arch.
1. A force that produces motion.
2. A continuous force applied by one object on another.
Word Tutor:
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thrust
IN BRIEF: To push with sudden force.
Be not afraid of greatness: . . . Some are born great, Some achieve greatness, And some have greatness thrust upon them.
— William Shakespeare (1564-1616)
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The forward aerodynamic force produced by a propeller, fan, or turbojet engine as it forces a mass of air to the rear of the airplane.
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categories related to 'thruster'
- Surfing
- Fox Hunting - thruster: rider who remains at front of field in fox hunt
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Thrust
For other uses, see Thrust (disambiguation).
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Thrust is a reaction force described quantitatively by Newton's second and third laws. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction on that system.
In mechanical engineering, force orthogonal to the main load (such as in parallel helical gears) is referred to as thrust.
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Contents
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Examples
A fixed-wing aircraft generates forward thrust when air is pushed in the direction opposite to flight. This can be done in several ways including by the spinning blades of a propeller, or a rotating fan pushing air out from the back of a jet engine, or by ejecting hot gases from a rocket engine. The forward thrust is proportional to the mass of the airstream multiplied by the change in velocity of the airstream. Reverse thrust can be generated to aid braking after landing by reversing the pitch of variable pitch propeller blades, or using a thrust reverser on a jet engine. Rotary wing aircraft and thrust vectoring V/STOL aircraft use engine thrust to support the weight of the aircraft, and vector sum of this thrust fore and aft to control forward speed.
Birds normally achieve thrust during flight by flapping their wings.
A motorboat generates thrust (or reverse thrust) when the propellers are turned to accelerate water backwards (or forwards). The resulting thrust pushes the boat in the opposite direction to the sum of the momentum change in the water flowing through the propeller.
A rocket is propelled forward by a thrust force equal in magnitude, but opposite in direction, to the time-rate of momentum change of the exhaust gas accelerated from the combustion chamber through the rocket engine nozzle. This is the exhaust velocity with respect to the rocket, times the time-rate at which the mass is expelled, or in mathematical terms:
where:
- T is the thrust generated (force)
is the rate of change of mass with respect to time (mass flow rate of exhaust);- v is the speed of the exhaust gases measured relative to the rocket.
For vertical launch of a rocket the initial thrust must be more than the weight.
Each of the three Space Shuttle Main Engines can produce a thrust of 1.8 MN, and each of the Space Shuttle's two Solid Rocket Boosters 14.7 MN, together 29.4 MN. Compare with the mass at lift-off of 2,040,000 kg, hence a weight of 20 MN.
By contrast, the simplified Aid for EVA Rescue (SAFER) has 24 thrusters of 3.56 N each.
In the air-breathing category, the AMT-USA AT-180 jet engine developed for radio-controlled aircraft produce 90 N (20 lbf) of thrust.[1] The GE90-115B engine fitted on the Boeing 777-300ER, recognized by the Guinness Book of World Records as the "World's Most Powerful Commercial Jet Engine," has a thrust of 569 kN (127,900 lbf).
Thrust to power
The power needed to generate thrust and the force of the thrust can be related in a non-linear way. In general, 
. The proportionality constant varies, and can be solved for a uniform flow:
Note that these calculations are only valid for when the incoming air is accelerated from a standstill - for example when hovering.
The inverse of the proportionality constant, the "efficiency" of an otherwise-perfect thruster, is proportional to the area of the cross section of the propelled volume of fluid (
) and the density of the fluid (
). This helps to explain why moving through water is easier and why aircraft have much larger propellers than watercraft do.
Thrust to propulsive power
A very common question is how to compare the thrust rating of a jet engine with the power rating of a piston engine. Such comparison is difficult, as these quantities are not equivalent. A piston engine does not move the aircraft by itself (the propeller does that), so piston engines are usually rated by how much power they deliver to the propeller. Except for changes in temperature and air pressure, this quantity depends basically on the throttle setting.
Now, a jet engine has no propeller. So let's find out the propulsive power of a jet engine from its thrust. Power is the force (F) it takes to move something over some distance (d) divided by the time (t) it takes to move that distance [2]:
In case of a rocket or a jet aircraft, the force is exactly the thrust produced by the engine. If the rocket or aircraft is moving at about a constant speed, then distance divided by time is just speed, so power is thrust times speed:[3]
This formula looks very surprising, but it is correct: the propulsive power (or power available [4]) of a jet engine increases with its speed. If the speed is zero, then the propulsive power is zero. If a jet aircraft is at full throttle but is tied to a very strong tree with a very strong chain, then the jet engine produces no propulsive power. It certainly transfers a lot of power around, but all that is wasted. Compare that to a piston engine. The combination piston engine–propeller also has a propulsive power with exactly the same formula, and it will also be zero at zero speed –- but that is for the engine–propeller set. The engine alone will continue to produce its rated power at a constant rate, whether the aircraft is moving or not.
Now, imagine the strong chain is broken, and the jet and the piston aircraft start to move. At low speeds:
The piston engine will have constant 100% power, and the propeller's thrust will vary with speed
The jet engine will have constant 100% thrust, and the engine's power will vary with speed
This shows why one cannot compare the rated power of a piston engine with the propulsive power of a jet engine – these are different quantities (even if the name "power" is the same). There isn't any useful power measurement in a jet engine that compares directly to a piston engine rated power. However, instead of comparing engine performance, the gross aircraft performance as complete systems can be compared using first principle definitions of power, force and work with the requisite considerations of constantly changing effects like drag and the mass (of the fuel) in both systems. There is of course an implicit relationship between thrust and their engines. Thrust specific fuel consumption is a useful measure for comparing engines.
See also
- Aerodynamic force
- Astern propulsion
- Gimballed thrust, the most common thrust system in modern rockets
- Stream thrust averaging
- Thrust-to-weight ratio
- Thrust vectoring
- Tractive effort
References
- ^ "AMT-USA jet engine product information". Archived from the original on 2006-11-10. http://web.archive.org/web/20061110025303/http://usamt.com/Mel/comm/comm_products.html. Retrieved 2006-12-13.
- ^ "Convert Thrust to Horsepower By Joe Yoon". http://www.aerospaceweb.org/question/propulsion/q0195.shtml. Retrieved 2009-05-01.
- ^ "Introduction to Aircraft Flight Mechanics", Yechout & Morris
- ^ "Understanding Flight", Anderson & Eberbaht
This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)
Translations:
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Thrust
Dansk (Danish)
v. tr. - støde, bore, stikke, mase, puffe, skubbe
v. intr. - bane sig vej
n. - stød, udfald, puf, stik, tryk, fremstød
idioms:
- thrust upon tvinge åben
Nederlands (Dutch)
duwen, toesteken, een weg banen, uitsteken, stoot, steek, (stuw-, drijf)kracht
Français (French)
v. tr. - mettre brusquement, enfoncer qch dans, passer brusquement, pousser violemment
v. intr. - percer, enfoncer (dans), pousser (dans), se frayer un passage
n. - (lit, gén, Mil, Tech, Archit) poussée, portée (d'une discussion), pointe (dirigé contre)
idioms:
- thrust upon imposer sur, faire endosser
Deutsch (German)
n. - Stoß, Hieb, Stich, Seitenhieb, Vorstoß, Schub
v. - aufhalsen, zustechen, stoßen, sich drängen
idioms:
- thrust upon aufhalsen
Ελληνική (Greek)
n. - σπρωξιά ή απώθηση, ώθηση, φραστική επίθεση, έντονη και συνεχής πίεση, μπήξιμο, νύξη, πλήγμα με αιχμηρό όπλο
v. - μπήγω/-ομαι, καρφώνω/-ομαι, χώνω/-ομαι, σπρώχνω βίαια, διαπερνώ, διασχίζω, περνώ
idioms:
- thrust upon φορτώνω με κάτι, επιβάλλω
Italiano (Italian)
forzare, infilare, infilzare, spingere, spinta, coltellata, forza motrice
idioms:
- thrust upon affibbiare
Português (Portuguese)
n. - empurrão (m), impulso (m)
v. - meter, enfiar
idioms:
- thrust upon impor
Русский (Russian)
колоть, резко толкать, тыкать, силой продвигаться вперед, колющий удар, продвижение вперед при применении силы
idioms:
- thrust upon заставить кого-л. сделать/принять что-л. против его воли
Español (Spanish)
v. tr. - empujar, impeler, clavar, meter, introducir
v. intr. - empujar, meterse, introducirse, abrirse paso
n. - empujón, estocada, arremetida, pulla
idioms:
- thrust upon imponer, forzar a aceptar
Svenska (Swedish)
n. - stöt, knuff, anfall, huvudriktning, huvudtema, drivkraft, kläm, drive
v. - sticka, stoppa, köra, stöta, tvinga, anfalla, knuffa, driva
中文（简体）(Chinese (Simplified))
插入, 刺, 猛推, 戳, 插, 猛攻, 突进
idioms:
- thrust upon 强迫..., 把...强加于...
中文（繁體）(Chinese (Traditional))
v. tr. - 插入, 刺, 猛推
v. intr. - 插入, 戳, 刺
n. - 猛推, 插, 刺, 猛攻, 突進
idioms:
- thrust upon 強迫..., 把...強加於...
한국어 (Korean)
v. tr. - 밀다, 찌르다, 억지로 ~ 시키다
v. intr. - 떠밀다, 돌진하다, 밀치다
n. - 밀침, 습격, 전진
idioms:
- thrust upon 억지로 떠맡기다, 떠맡겨 팔다
日本語 (Japanese)
v. - 強く押す, 突き進む, 突っ込む, 突き刺す, 押し出す, 押し込む, 差し出す
n. - 押し, 猛攻撃, 激しい攻撃, 推進力, 酷評, 攻撃, 推力
idioms:
- thrust upon 押し付ける
العربيه (Arabic)
(الاسم) قوة دافعه, ألدفع (فعل) يقحم, يدفع
עברית (Hebrew)
v. tr. - דחף, דחק, פילס (דרך) בכוח, הטיל או כפה על
v. intr. - נדחק, תקף בכידון, דקר, תקע
n. - דחיפה, תחיבה, נעיצה, לחץ, מכה, מהלומה, התקפה, עקיצה, מתח בין חלקי קשת, כוח-הדחף של מנוע רקטי סילוני
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