Continental O-200

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jwocky
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Re: Continental O-200

Postby jwocky » Thu May 19, 2016 4:47 pm

Yep, the idea the fuel consumption is too high comes from what you said, you had to reduce the BSFC to make it work in the consumption parameters. A part of it was because of the sparkfaildrop problem which included basically the loss doube. So to some degree you have to reduce BSFC, but thne, there is still some unexplained part of this reduction.

Looking at the data, what do we have mathematically here?
Clearly, it's a set of curves, depending on mixture in a set of curves depending on %power in a set of curves depending on altitude and so on. Alas, we have not enough data points to calibrate such a monster. However, if we get the data for the same model of thinking out of the existing simulated engine, we can probably reduce/increase this base curve till it fits at least those three data points we have. It would be an approximation though. But it's a lot of math work. For such things people use super computers lol. So we will probably not achieve the needed granularity.

Honestly, am I walking off in some kind of mathematical swamp here?
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bomber
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Re: Continental O-200

Postby bomber » Fri May 20, 2016 8:52 am

My thoughts are yes....

Why do I think that... because you can only use what you've got... and you've got a JSBsim program of a piston engine and not a real engine.
So you can only play within the parameters that's been given to us, we can point out any changes that we feel need doing, but we can't make that happen.

Anyway final test on the engine was to run it at sea level using 75% power at 2500rpm at 95kts and check the cylinder head temp.. normal is anywhere between 300-420F...

Test Results with a cooling factor of 0.36

Cylinder Head Temperature = 360F
Oil pressure = 64psi
Oil Temperature = 159F
HP = 75
Fuel consumption = 5.4g/hr




Simon
"If anyone ever tells you anything about an aeroplane which is so bloody complicated you can't understand it, take it from me - it's all balls" - R J Mitchell

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jwocky
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Re: Continental O-200

Postby jwocky » Fri May 20, 2016 12:27 pm

Errrr .... I don't see the problem?

360F is in the green area.
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bomber
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Re: Continental O-200

Postby bomber » Fri May 20, 2016 12:30 pm

There isn't one... just the oil pressure isn't in the green
"If anyone ever tells you anything about an aeroplane which is so bloody complicated you can't understand it, take it from me - it's all balls" - R J Mitchell

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jwocky
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Re: Continental O-200

Postby jwocky » Fri May 20, 2016 12:43 pm

Yeah, but pure by instinct (and having seen some exorbitant oil pressures from JSB on other planes), I would look first whether JSB maybe has a glitch in there.
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