Linked Questions

24
votes
6answers
8k views

In what way are the Concorde's engines considered efficient?

The Concorde is powered by a bunch of Rolls-Royce/Snecma Olympus 593 turbojet engines. Much has been said about how efficient they are at speed, and the fact that they allow long-range cruise at Mach ...
12
votes
4answers
4k views

Can I simply use multiple turbojet engines to fly supersonic?

the jet engine FJ33 produced by Williams International produces around 6 kN thrust (maximum, at sea level). Imagine: to fly supersonic, I need for my aircraft 9 kN of continious thrust. I am wondering ...
16
votes
5answers
3k views

Why is thrust inverse to speed in piston engines?

It is said that piston engines have constant power output, and thus their thrust is inverse to speed (e.g. here), while turbines have relatively constant thrust. I'm looking for an intuitive ...
27
votes
1answer
15k views

Is there any equation to bind velocity, thrust and power?

I am designing a remote controlled airship. I will tune it so that the lift given by Archimedes' Principle will exactly balance the weight of all the structure. It will be propelled by brushless ...
12
votes
4answers
3k views

What is a ramjet?

What is a ramjet? Was it used on the SR-71 Blackbird?
12
votes
2answers
7k views

How (and why) does engine thrust change with airspeed?

I'm interested in how the thrust of a turbofan engine is affected at higher airspeeds (TAS). I know (I believed) that engine thrust(at constant N1) was relatively constant like in the following graph (...
9
votes
2answers
4k views

Which aircraft endure the highest Max Q's (aerodynamic pressure)?

What are the highest aerodynamic pressures encountered in any aircraft? And does this limit the maximum speed of any aircraft at certain altitudes? Broadly, 'how fast can you go [at a given altitude]?'...
3
votes
4answers
2k views

What drives the shape of an engine's intake on a fighter jet?

Rectangular intakes have more corners which might increase subsonic pressure losses and would weigh larger than a pitot (Semi-circular) type intake. Are the designer drivers solely based on supersonic ...
2
votes
1answer
482 views

Does jet engine exhaust velocity relative to itself remain constant despite speed changes?

Maybe this is a stupid question. I seem to have been told, the velocity of the exhaust leaving an airbreathing jet engine relative to the engine, is constant despite changes in airspeed. However, to ...
0
votes
2answers
219 views

What´s the logic behind the Power Curve?

Aircaft thrust is what counteracts drag, but in flight school they tought us that propeller aircraft are "power producers" and not thrust producers as jets. (That´s because the propeller ...
1
vote
3answers
148 views

Why does power go up with the cube of the airspeed?

If i have an airplane with over 100 kN of thrust, and i want to accelerate from a velocity at which drag force is 25kN to a velocity twice higher, is it possible that i wont be able to do this because ...