horse power of the 737 jet engine?

Answer 1

The above poster is correct that jet engines are not rated in horsepower rather they are rated in pounds of thrust. According to the Boeing website, the current 737 has engines that are rated at 22,700 lbs of thrust each. You really can't compare the two different values of thrust and horsepower. It would be like comparing apples to oranges.

I got the following info from http://inventors.about.com/library/inventors/blhowajetengineworks.htm
"At approximately 400 mph, one pound of thrust equals one horsepower, but at higher speeds this ratio increases and a pound of thrust is greater than one horsepower. At speeds of less than 400 mph, this ratio decreases."
So you see, it is very hard to compare the two values.

Answer 2

As mentioned above the power-rating is related to the thrust multiplied by the flight-speed.

The reason for this is that power is defined as rate of work done, that is, energy per unit time. When the aeroplane flies forward it incurs drag, that drag is compensated for by the engines. So, when the plane flies at a speed V, its engines feel like they are pushing against a load.

If you waited a unit time, say one second, you could say that the engines had done an amount of work LOAD x DISTANCE... if you wanted to know how quickly they were doing work, you could then take the derivative of this expression to find it.

if F(t) = thrust in Newtons of course...
s(t) = distance in metres

Then power should be F(t)ds(t)/dt + s(t)dF(t)/dt

If we consider the thrust constant, which with relation to Velocity and altitude it nearly is in most aircraft, the expression simplifies to Fds(t)/dt =FV

The REASON why the ratings are done differently is because for jet engines and rockets any throttle control regulates the thrust, because of the way the engine works expanding gases out of a nozzle. For aeroplanes driven by propellers, the energy of the gases is taken up by turbines and put into the propeller via a drive-shaft, in this case, controlling the fuel available for burning directly influences power available. The exact reasons for this are beyond the current scope.

Finally, please note that the "power required" for flight at a certain speed is still the determining factor for the flight-dynamics and so its hardly "apples and pears" in practice because it is still power that matters to maintaining airspeed and thrust when for want of a simple example, working out whether an aircraft would be able to stand on its tail and still accelerate from a standing start.

Addendum

Power in Watts,
Energy (work-done) in Joules
Metric measurements require few or no conversions and are a bit more modern... you know... like men not wearing tights anymore.

Answer 3

Jet Engines not rated in Horse Power.

Answer 4

Jet engines are rated in pounds of thrust, not horsepower. The engines on the 800 series are rated at a maxium thrust of 27,300 lbs.

Using the formula related thrust to horsepower or THP=F x speed(mph)/375, where THP is thrust horsepower, F is thrust in pounds, and then speed in mph, then:

27,300 lbs is maximum thrust
530mph is typical cruise speed

THP=27300 x 530mph/375, so thrust horsepower on a 737 would be 38,584.

Answer 5

The accepted definition of horsepower is 550 foot pounds per second. Take the takeoff weight of the plane and it's rate of climb, (feet per second) and get your measure of "horsepower". An interesting measure of efficiency would be to take the btu's used to calculate the efficiency as .707 btu's per second is "one horsepower", as is 746 watts.

A 150,000 pound 737 flying at 500 miles per hour has a lift to drag ratio of about 18 to one, meaning that the engines have to "thrust" about 8,300 pounds to maintain that speed. 500 mph = 733 ft per second. So...... 8,300 x 733 divided by 550 equals 11,000 horsepower in cruise. (for two engines). Takeoff "horsepower" is much more but I could not quickly find the rate of climb for the 737 specs. Interestingly, the engine thrust for cruise is publicized at about 4,500 pounds which came pretty well on the mark of the educated guess.

Answer 6

Thrust Horsepower

Answer 7

one pound of thrust equals about 2 hp. so 27,000 lbs of thrust give or take would be 54000 hp/engine

Answer 8

You may visit the official Boeing site for more information in addition to others....