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Michael2 avatar image
Michael2 asked mattnischan answered

Don't understand new turbine efficiency variables

I am a little confused by the new SimVars TURB ENG THRUST EFFICIENCY LOSS, TURB ENG FUEL EFFICIENCY LOSS, and TURB ENG N1 LOSS. The SDK doesn't indicate how these are supposed to work. In the aircraft I am developing the values are always zero.

Is the intention that the developer controls the values directly? If so, how are we to write to them? I don't see any associated event IDs.

Or is the expectation the sim engine will change the values on its own. For example if I turn on engine or wing anti-ice should I see one or more of these SimVars change? For the record, I don't see any such effect.


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5 Answers

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Flysimware avatar image
Flysimware answered Flysimware edited

This is a writeable variable so there never was an event. You write directly to the Avar.

An example for logic would be...

'if true statement' if{ 50 (>A:TURB ENG THRUST EFFICIENCY LOSS:1,Percent) }

This would cause engine 1 to loss half the thrust power.

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Michael2 avatar image
Michael2 answered

Well, that would be great if I could get it to work. I already tried that and it doesn't. The value stays at zero. I take it you have this working?

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Michael2 avatar image
Michael2 answered Michael2 edited

OK, I persisted with this and am seeing the desired effects writing to the A vars. The weird thing is that I can't read these vars directly. I don't use the var watcher utility. I just have a reference section in my xml code where I write Avars into Lvars with the same name for any Avars I want to monitor for debugging. I then use the behavior window to see the values. Doesn't work with these new variables.

Put another way, I can write to these variables, but can't read them.

Thanks for your help.

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Michael2 avatar image
Michael2 answered Simbol edited

Another bug with these. The units are expressed to be Percent, but to get a 2% loss in thrust I have to put in 0.02. As in 0.02 (>A:TURB ENG THRUST EFFICIENCY LOSS:1,Percent). The units should be stated as Percent over 100. If I put in 2 instead of 0.02 the engine's thrust will drop to zero.

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Simbol avatar image Simbol commented ·

Right this explain my results!.


@Boris_ can we get the documentation corrected? I thought this was not working until I confirmed Michael results, now I have this working correctly.

Best,
Raul

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mattnischan avatar image
mattnischan answered

Hello,

These are not variables that are controlled by the sim. Instead these are variables intended to be used by developers to decrease the efficiency of the indicated engine parameters, in order to simulate things like bleed air load efficiency loss, engine wear, damage, etc.

Setting the var should work with either Percent (0 to 100) or Percent Over 100 (0 to 1), although it is represented as 0 to 1 internally.

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