Engine idle regime at minimun throttle
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I meant between different engines - so GE-100 in BMS is different logic to GE-129?
This is very cool
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I meant between different engines - so GE-100 in BMS is different logic to GE-129?
This is very cool
yes they are different, but not on every aspect, as in real :
for isntance
GE 100 MIL RPM is 1.03 while GE 129 is 1.08
max AB RPM : 1.04 vs 1.08
spoolrates are different
FTIT are different (not sure in 4.33 though…)
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…we’re not talking % RPM here, right? But limiting Mach?
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We are talking about engine logic in general and yes different engines are modeled In those areas
Rpm , nozzle posit , ftit , spool times etc….
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I know that some engines have a speed lockup which happens in conjunction with Mach (some GE engines being of that case). Sometimes that’s also influenced by the inlet…so it can vary from model to model even for the same engine. I’ll consult the Dash 1.
But still - “1.03” what?
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I know that some engines have a speed lockup which happens in conjunction with Mach (some GE engines being of that case). Sometimes that’s also influenced by the inlet…so it can vary from model to model even for the same engine. I’ll consult the Dash 1.
But still - “1.03” what?
Guessing he is talking about max RPM. 103% and 108%
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Knowing what I do about the F110, that doesn’t quite make sense…that engine isn’t allowed to over-speed. At least it wasn’t as I knew the GE engine back in the mid 80s…but that was a long time ago, in another of my lives.
But it would make sense that it has a speed limiter of some sort - fan speed, I think. Plus I’ve never heard rotor speeds expressed that way…always only as numbers like 000.0%. The Dash 1 says the Pratt engine is limited to 97% steady state and 98% transient; and the GE to 108% steady state, and 109% transient. Which is still odd to me, but that’s what the book says…and I’d expect them to lock to those numbers in certain circumstances - generally driven by Mach/inlet recovery/flow limitations. Which is what it sounds more to me like what BMS is modeling.
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Knowing what I do about the F110, that doesn’t quite make sense…that engine isn’t allowed to over-speed. At least it wasn’t as I knew the GE engine back in the mid 80s…but that was a long time ago, in another of my lives.
But it would make sense that it has a speed limiter of some sort - fan speed, I think. Plus I’ve never heard rotor speeds expressed that way…always only as numbers like 000.0%. The Dash 1 says the Pratt engine is limited to 97% steady state and 98% transient; and the GE to 108% steady state, and 109% transient. Which is still odd to me, but that’s what the book says…and I’d expect them to lock to those numbers in certain circumstances - generally driven by Mach/inlet recovery/flow limitations. Which is what it sounds more to me like what BMS is modeling.
What does 100% mean ? This is just a matter of norm !
And all our data have been cross checked zillions time
Be aware that in real rmp is evolving around a value , and is different from engine to engine (even with the same engine type) and with external condition . This is not modeled
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Hi guys!
Since we are talking about F-16 engines … I would need to know what are the specific REAL LIFE “standard” following values for the our simulated F-16 engines:
FTIT Start (normal/common T° peak on engine start)
FTIT Idle (normal/common T° at idle)
FTIT Max (normal/common T° full dry)
FTIT AB (normal/common T° full AB)For the following engines:
In priority I need:
F110-GE-100
F100-PW-200
F100-PW-220Additionally (because I already received recommendations/references for those, but with more I could cross check)
F110-GE-129
F100-PW-229…
Note: I am NOT asking the values shown in the REAL Dash-1 (nor in BMS -1 but the one published in any other REAL engine technical documentation or the one shown in REAL fight! In -1, there are only the limitations, but normal ops values are below those maximum acceptable values. What I need are the generally observed common/normal values.
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If you are after the FTIT values BMS produces, I can do a quick test run presently for you…?
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Hi guys!
Since we are talking about F-16 engines … I would need to know what are the specific “standard” following values for the our simulated F-16 engines:
FTIT Start (normal/common T° peak on engine start)
FTIT Idle (normal/common T° at idle)
FTIT Max (normal/common T° full dry)
FTIT AB (normal/common T° full AB)For the following engines:
In priority I need:
F110-GE-100
F110-GE-129Additionally (because I already received recommendations/references for those, but with more I could cross check)
F100-PW-200
F100-PW-220
F100-PW-229…
Note: I am not asking the values shown in the Dash-1! In -1, there are only the limitations, but normal ops values are below those maximum acceptable values. What I need are the generally observed common/normal values.
You should have values for the GE 129 and PW-229 in one of your pm’s ages ago.
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If you are after the FTIT values BMS produces, I can do a quick test run presently for you…?
LOL
i think DeJay does not need help to check what values are in BMS
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If you are after the FTIT values BMS produces, I can do a quick test run presently for you…?
No real one of course.
You should have values for the GE 129 and PW-229 in one of your pm’s ages ago.
Sorry … my post was wrong! Correcting it! Thank you leech!
But anyway … if we can have other sources it is good also.I still don’t have any reliable source for the others.
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For the F-16CM-40 (F110-GE-100):
FTIT Start (normal/common T° peak on engine start): after throttle is advanced to IDLE, FTIT steadily increases towards 550°, reaching it at 70% RPM. FTIT then rapidly falls to 480° and remains steady there at IDLE.
FTIT Idle (normal/common T° at idle): On the ground, 480°. In the air, higher depending on airspeed (possibly altitude, also?). 550° observed at 14k, 300 KCAS. 480° observed at 14k, 0 KCAS.
FTIT Max (normal/common T° full dry): 730° seemed a constant, despite varying altitude and airspeed extensively.
FTIT AB (normal/common T° full AB): 745° to 748° - unsure if the variation is in my readings of the gauge, or actual variations in the FTIT. The higher readings come from flying faster, so perhaps its an actual variation?Ah. Ive misread your post, then - it seemed to be asking for the values from the simulated engines, vice the real ones…!
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Thank you Blu3Wolf but are those the real one? … I don’t need the BMS values, I an check them myself … I need the REAL one.
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No, those are the BMS values, per your post asking for the BMS values.
Note: I am not asking the values shown in the Dash-1! In -1, there are only the limitations, but normal ops values are below those maximum acceptable values. What I need are the generally observed common/normal values.
But the manual does have the normal ops values for some engines… specifically, the PW220. For whatever reason, it doesnt have a normal value listed for the PW229, the GE100 or the GE129 - either the writer didnt have them, or the values vary more significantly depending on conditions/other factors.
PW220 Non AB Operation: After a MIL takeoff, FTIT is usually 890°-960°C with rpm of 89-94 percent for any outside air temperature above 2°C. FTIT and engine rpm are lower for temperatures below 2°C.
Regardless of temperature, nozzle position should not exceed 30 percent at MIL.
Engine operation is continually optimized as flight conditions change. This is evident by slight changes in the NOZ POS, RPM, and FTIT indicator indications.
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No, those are the BMS values, per your post asking for the BMS values.
Ok … post updated:
Hi guys!
Since we are talking about F-16 engines … I would need to know what are the specific REAL LIFE “standard” following values for the our simulated F-16 engines:
FTIT Start (normal/common T° peak on engine start)
FTIT Idle (normal/common T° at idle)
FTIT Max (normal/common T° full dry)
FTIT AB (normal/common T° full AB)For the following engines:
In priority I need:
F110-GE-100
F100-PW-200
F100-PW-220Additionally (because I already received recommendations/references for those, but with more I could cross check)
F110-GE-129
F100-PW-229…
Note: I am NOT asking the limitation (max) values shown in the REAL Dash-1 (nor in BMS -1 but the one published in any other REAL engine technical documentation or the one shown in REAL fight! In -1, there are only the limitations, but normal ops values are below those maximum acceptable values. What I need are the generally observed common/normal values.
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What does 100% mean ? This is just a matter of norm !
And all our data have been cross checked zillions time
Be aware that in real rmp is evolving around a value , and is different from engine to engine (even with the same engine type) and with external condition . This is not modeled
That’s not what I’m asking about - I’m asking what the numbers you cite like “1.03” are referenced to. Those numbers look like Mach and not spool speeds to me, as “1.03” would be sub-idle, to me. WAY sub idle…if you actually mean “103%”, that would be how I’m familiar with such - maybe Pratt does things different? Language barrier…
As a former engine designer (in that fore mentioned lifetime) I can tell you that “100%” refers to physical rotor speed divided by design physical rotor speed…and that was always one of my recurring questions during the time I was working at GE - what is 100% physical speed (for whatever I happened to be working on)? It seemed to matter when I was in Compressor Mechanical Design…
Any operation not at 100% is considered “part power” or “off design” and everything the control system does (or tries to do) is to optimize that off-design operation. But during the time I spent in Controls nobody much seemed to care what 100% physical speed was/is - everything was just referenced in percent terms…and that was always expressed as a number like 000.0%.
What I’m even more curious about is why the gauge for the GE engine goes to 110% instead of 100%…not that it matters, it’s just curious. As you say - “100% RPM” is arbitrary. The only other time I’ve seen such is for the RR Pegasus - 102.5% SLW, and then I also seem to recall a time limit on that…
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@Dee-Jay - the answer is a bit more complex than you’d like it to be. All of this data really vary with speed/temperature/altitude/installation…for each engine. This is why all of these parameters are only stated as ranges. If BMS models a Standard Atmosphere, then you could make some predictions based on that, but in general what you’d see in flight dynamically shouldn’t strictly hold to that.
The Limits presented in the Dash 1 are really what’s important - so I’d suggest looking for older copy of the Dash 1 for older engines. The engine’s control system should try to keep you away from these limits, operative being “try”. You can hot/wet start the engine if you’re ham-fisted with the throttle in RL (AB too, under certain circumstances) and I’m not sure just how you’d model that in BMS, on a casual thought.
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That’s not what I’m asking about - I’m asking what the numbers you cite like “1.03” are referenced to. Those numbers look like Mach and not spool speeds to me, as “1.03” would be sub-idle, to me. WAY sub idle…if you actually mean “103%”, that would be how I’m familiar with such - maybe Pratt does things different? Language barrier…
As a former engine designer (in that fore mentioned lifetime) I can tell you that “100%” refers to physical rotor speed divided by design physical rotor speed…and that was always one of my recurring questions during the time I was working at GE - what is 100% physical speed (for whatever I happened to be working on)? It seemed to matter when I was in Compressor Mechanical Design…
Any operation not at 100% is considered “part power” or “off design” and everything the control system does (or tries to do) is to optimize that off-design operation. But during the time I spent in Controls nobody much seemed to care what 100% physical speed was/is - everything was just referenced in percent terms…and that was always expressed as a number like 000.0%.
What I’m even more curious about is why the gauge for the GE engine goes to 110% instead of 100%…not that it matters, it’s just curious. As you say - “100% RPM” is arbitrary. The only other time I’ve seen such is for the RR Pegasus - 102.5% SLW, and then I also seem to recall a time limit on that…
1.03 means 103 on the rpm gauge in the cockpit