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Old 02-26-2018, 11:43 PM
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SALMONBUG
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Originally Posted by Woketman View Post
Dean is correct. There is plenty of free intake area in a normal install on this plane. It ain't gonna make any difference in thrust on any turbine. No shortage of intake area at all.
the main discussion was not about the design of the intake aera of the R54 but about the effect of partialy mask the air intake in general. The discussion started around the fact some modelers drill the R54 boat tail to be able to correcti the balance by moving the starter inside the boat tail , this move the air intake closer to the boat tail.

Maybe my wrong english makes that what I writte doesn't reflect what I want to say, so I will writte very simple phrases that reflect what I want to say .The two next lines :

Some people says that the for a given rpm on a given turbine engine, the shape of the inlet has no effect on the thrust........

What I say is simply that this is not thrue.........


In some case the difference can be unsignificant ( and I am sure this is the case on the modification we are talking about on the particular R54)
What we should be aware about when discussing about this is that rc jet engines are extremely primitive designs and the way we install them is also extremely empiric.
For exemple of the ruticity of our engines I will simply say for example that the name "reaction 54" is because the plane prototype's engine was build around a 54 mm centrifugal compressor coming right out of a car turbo.
by comparison I would say that the bmw003 ( engine fitting the first real heinkel he162 during ww2) was already fit with a 7 stage axial compressor.
What made possible the developement of RC turbine engines is not the engine concept itsfel, it's the developpement of the small electronic component that made possible to build ECU smaller than a shoebox
The engines are primitive because they are cheap, they are easy to operate, the maintenance is unsignificant and also nobody care about the cost of the jet A1 for a sunday flight session and also nobody would be ready to pay for the developement of rc engines fitted with compressor stall protection ( like variable stator vanes and so on)
We buy them, we install them and they do the job as soon we follow some general rules and we don't care about the limit of the performances, we fly.and we have fun !!!

If the engine, surge,, broken or flameout, we crash and we start a new winter project. We don't kill anybody

This discussion is deviating from the main subject of this thread, that's my last post about it. I'll be happy to discuss this subject in PM

Enjoy building and flying your r54

Last edited by SALMONBUG; 02-27-2018 at 01:48 AM.
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