FS2004 Override Throttle settings

[vololiberista]

I've had a little play and what I tried didn't seem to work so I'm wondering if it is possible.
If I set my throttle to 100% at ISA I get 102% n2 -- fine.
Obviously if the temperature rises then the throttle setting to obtain 102% n2 lowers.
I tried using ambient temperature to create a fake throttle setting as it were. But it always seems to be overriden by the real throttle.
So in other words I want to set the physical throttle to 100% and the actual n2% output to change according to the temperature. Can that be done?

 

[Roy Holmes]

Although this thread addressed FSX/P3D I see no reason why it should not apply to FS2004.
http://www.fsdeveloper.com/forum/threads/p3d-fsx-effect-of-ambient-temperature.432915/
In the first post N1 rose with temperature. Given your N1/N2 relationship N2 should also rise.
No action required, the sim does it already
Roy

 

[vololiberista]

Thanks Roy,
As far as I'm aware (awaiting confirmation) the throttle is not advanced to max on a hot day. Reason being that on say ISA+15 n2 would far exceed the engine limitations schedule. The RR Conway was/is not a FADEC controlled engine. It is instead controlled by Mk1 eyeball of the EO!
My guess so far if confirmed is
ISA 100% TLA
ISA+5 98% TLA
ISA+10 92% TLA
ISA+15 90% TLA

In fact at SL at ISA on a long take-off run N2 would be at 102% at rotation. The limitation is 5 minutes at 102%.
On hot days n2 can go up to 105% for which the limitation is only 20 seconds.

As you say the sim models this correctly.

 

[vololiberista]

Here's another Q. Is it possible to reduce fuel flow according EGT. For example if EGT reaches 595c?

 

[Roy Holmes]

Only if you had some code that reduced throttle and hence thrust when the EGT hit some value. Fuel flow is proportional to net thrust in the Sim. I forget if FS9 has a TSFC config entry, but in any case a fuel flow scalar of 1.0 corresponds to a TSFC of 0.5.
Roy

 

[vololiberista]

Only if you had some code that reduced throttle and hence thrust when the EGT hit some value. Fuel flow is proportional to net thrust in the Sim. I forget if FS9 has a TSFC config entry, but in any case a fuel flow scalar of 1.0 corresponds to a TSFC of 0.5.
Roy

Thanks Roy,
I'll see if I can change anything

 

[Heretic]

The L-39 uses a fuel governor that prevents the engine from running at more than 700°C EGT.

I've implemented this by countering throttle movement if the EGT is above 695°C.

  (P:ABSOLUTE TIME, seconds) (G:Var2) - 1 >
  if{ (P:ABSOLUTE TIME, seconds) (>G:Var2)
  (A:GENERAL ENG EXHAUST GAS TEMPERATURE:1,celsius) (>G:Var3)
  }
  (A:GENERAL ENG EXHAUST GAS TEMPERATURE:1,celsius) (G:Var3) - (>L:Delta_EGT,number)
 
  (A:GENERAL ENG EXHAUST GAS TEMPERATURE:1,celsius) 695 >
  (L:Delta_EGT,number) 0 >
  and
  if{ (A:GENERAL ENG THROTTLE LEVER POSITION:1, percent) (L:Delta_EGT,number) 10 * - 163.83 * (>K:THROTTLE_SET) 1 (>G:var4) }
  els{ (A:GENERAL ENG THROTTLE LEVER POSITION:1, percent) 80 <   
  (G:var4) 1 ==
  and
  if{ 80 163.83 * (>K:THROTTLE_SET) 0 (>G:var4) } }

 

[vololiberista]

Thanks H I'll have a look at your code.