Transcriber: lisa thompson Reviewer: David DeRuwe
So how does a General Electric GEnx engine work?
The GEnx engine specialties are that only 10 percent of the air
actually gets ignited with the fuel;
the rest just gets blown out of the back of the engine.
Each engine is worth $34 million.
That's as much as, probably, two tons of gold.
It is the most expensive kind of engine.
I already said that.
This engine is only used on two aircraft.
It's the safest type of engine ever built.
The engine's insides -
I'll explain the parts from the front to the back.
So first, there's a sharp nose cone on the front of the engine.
This is to improve the aerodynamic flow into the engine.
Next are the fan blades.
Each fan blade is made out of four sheets of carbon fiber,
a strong but lightweight material.
It is also what the revolutionary 787 Dreamliner is made up of.
Then there's a huge pipe-looking cylinder called the housing.
This part keeps the fan blades from falling off
and gives the engine its unique shape.
Then there's the low pressure compressor.
This part receives a short burst of air from the fan blades,
which drives the combustion fan.
Then there's the high pressure compressor.
It receives a massive burst of air from the low pressure compressor
to drive the low pressure turbine, which I'll explain later.
Then there's the compressor.
This is where the fuel and the air are mixed and ignited with each other
to create forward motion to the rest of the engine.
Then there's the high pressure turbine.
This is where the mixed air gets blown into, to create -
it sends forward motion to the fan blades at the front.
Then it also drives the fan blades in the low pressure compressor,
which forces the combusted air into the rear cone and out the back.
So how does the engine work?
The engine works by sucking in air through the front.
It's compressed to 1/10 its original size.
Then the air and the fuel are mixed and ignited.
This creates a small, controlled explosion
that turns the fan blades in the turbines.
And the mixed air gets blasted out the back,
which creates the forward motion to the bigger fan blades,
which shoves the uncompressed air out the back.
So why do we need this engine?
Because it emits less greenhouse gases,
it has reduced the number of safety issues,
it has saved a lot of fuel costs,
and it's extremely quiet compared to other engines.
This engine is only used on two types of aircraft:
the 787 Dreamliner,
the world's most luxurious and advanced aircraft of the 21st century,
and the 747-8, the world's largest passenger airliner
and the greenest too.
Both are made by Boeing.
But there are some problems.
Even though this engine is sending us in the right direction,
there are a few drawbacks.
It is extremely expensive to make,
to build, and maintain.
It still emits greenhouse gases, but not as much as others.
It is extremely easy to freeze up or get too cold to produce thrust -
and are easy to break if not maintained for properly.
Even though these problems are bad, there are a lot of solutions.
As one of my favorite inventors said -
Wernher von Braun -
"I've learned to use the word 'impossible' with great caution."
So [we need] to create engines that do not have any of these problems:
engines that do not get too cold to produce thrust or to freeze up,
engines that are cheap and easy to manufacture,
engines that are really tough and hard to break,
and engines that have detailed maintenance manuals with the construction.
Have a safe and fun time flying.
See you in the air.
(Applause)