I was wondering why people dont make diffusers like the real ones and why dont they seal the exhaust. Is the pressure limit to close to introduce higher pressure air to the compressor. Why are people installing the way they are. isint the exhaust sucking the air out of the engine cavity creating lower pressure and starving the engine. why cant we make it a sealed system like the real ones and bring high pressure air to the compressor.

How do you keep the inside of the fuselage and pipe cool if you do this ?

1.) What is a diffuser?

2.) What does "seal the exhaust" mean?

If the engine will reach a reasonable equilibrium temp. then you wont need bypass air over it, maybe holes to blead pressure change. The existing exhaust i have seen looks like a trumpet, some of the air flowing out is exhaust and some is the air from the bypass.

More like the compressor creating high compressed air then burned to produce thrust. The turbine wheel do it all over again Not much can do with single stage engine.

did you mean single stage compressor, it cant hurt to make some high performance micro turbines can it.

drive the cost up, sure, anything can be done with enough money.

I think he means to weld the exhaust cone shut.


"serious business"

I would venture to say that "seal the exhaust" means "why is there a gap in the thrust tube to the engine" and it is not sealed or tight fitting. Of course pipe temperatures and EGT temps would be very high with a "sealed" pipe to the engine. The purpose of the gap is to allow cool air to be sucked in and therefore cool the pipe.....and in an enclosed bypass this action also cools the engine. I think as far as the diffuser is concerned, they are to reduce the speed of the incoming air, something which the models have no problem with.

The reason is simple.. All these engines are sensitive to back pressure or the exhaust.

With all the differnet planes and differnet engines it would require tunning each 6 to 36 inch long
sealed exhaust for that engine....

I tell you this.... It would make some planes much faster because the exhaust velocity would
be around twice as fast.. ( On a sleek plane)... But because most plane can get to 200 mph
it is something that is not required and too much trouble..

Eddie Weeks

those are reasonable answers. if i had a plane that was faster than 200mph than i dont think i could see the thing anyway.