YES - in by a huge amount
Which is why only the military uses jets!!
Those engines on the Airbus or Boeing you see they are not “jets” they are turbofans
The basic equation is simple
Thrust = mass flow rate x “exhaust” speed
But the Power = Mass flow rate x “exhaust” speed SQUARED
So the name of the game is to throw enough mass backwards fast enough to get the thrust you need
The faster you want to go the faster you need to throw the air backwards
So a slow aircraft uses a dirty big propeller to throw a lot of air relatively slowly - a helicopter is the ultimate example
As you go faster you use a smaller “propeller”- as in this “Turbofan engine”
If you want to go really fast like the military do THEN you use jets
You use the most efficient engine that will achieve the speeds that you need to achieve
And as the speeds go up the exhaust velocities go up and the amount of energy/fuel required goes up
EDIT
Had a few comments that todays jets are turbofans - and in truth there is something to that ALL jets are also turbofans
The difference is the amount of “Bypass” - with a spectrum where the faster the less bypass and the less “efficient” the engine is
Writer: Duncan Cairncross
