Make your own free website on Tripod.com

   
 How a Jet Engine Works

 

 

 

 

 

 

Home / Design Ideas / Contest / Science of Flight / Comparison Chart / Teachers-Parents / Email

 Click here for more on jet engines 

Come explore the answers to these and other curiosities you may have!

 

 

 

 

 

 

 

 

Sir Isaac Newton

 

 

 

 

 

 

 

 

 

 

Faster air means less air pressure (top)

Slower air means greater air pressure (bottom)

CONCLUSION:

Lift happens when the air pressure on the bottom side if the wing is GREATER than the air pressure on top of the wing.


How does the engine make the plane move?

Filling a balloon with air and letting it go is a simple explanation of how
a jet engine moves forward.

 

 

 

 

 

 

 

 

 

A jet engine get its forward motion by a forward reaction to the fast
moving jet gases moving out to the back of the jet engine.

For now, think of our jet engine as nothing more that a balloon with
moving parts. When the super fast moving jet gases rush out the back,
the engine has no choice but to move forward, just like a balloon.
This was explained by the mathematician Sir Isaac Newton a very long time ago.

Long before airplane engines were invented, Sir Isaac Newton,
back in the 1600's created what is now called the laws of motion.

Newton's third law
says that "for every action (force) there is an
equal and opposite reaction (opposite force)."
Newton's law is the
scientific reason why an object like a jet airplane will move forward
in reaction to the engine gases shooting out the back. The exhaust
of the high speed gases is the action. The engine moving forward -
that's the reaction.

CAUTION: the high speed gasses rushing out the back DO NOT push
against the outside air. If this was the case then how do we explain
how rockets move through space, where there is no air to push on!
In fact, a jet airplane would actually move forward easier in space
because unlike flying through the air an object like a plane would
not have to fight friction from the air molecules. The only problem
is steering, since wings can't create lift in space (no air).
But that's another story. [
>> ?'s ]


How does a plane take off the ground?

Attach a jet engine to an airplane and the plane will move forward on the airport "run way", faster and faster. Soon the airplane reaches a speed where the plane actually lifts off the runway and begins to climb into the sky!

How does this happen?

First, the jet engine or the engine with a propeller on a plane provides the force to move a plane forward faster and faster, to accelerate the plane down the runway. You can feel this acceleration when you sit in an airplane seat and the engines begins to r-o-a-r. The acceleration you feel comes as a reaction to the engine gases accelerating the air out the back of the engine - like a balloon.

Secondly, the forward and increasing speed made by the airplane engine causes the air to rush over the specially shaped wings of the airplane creating an upward force called LIFT. As the airplane speeds continues to increase the lifting forces on the wings becomes greater than the weight of the plane and it's passengers. When this happens the airplane lifts off the ground and begins to fly.

[ >> ?'s ]

 

 

How planes fly

More Jet Engines

 

 

 

 

 

 

 

return to top