Embarrassing question; Turboprops

[Lionheart]

Hey guys,

I thought I would post this hear. Some of the Developer forums are a bit slow lately, and alot of us hang out here.

Something that has always eluded me, and I could never figure out why this happens nor how it works.

What controls the 'spool up time' on a turboprop? Is this an airfile or config file tune? I have worked with many settings and cannot seem to get the turbine to spool up faster. (I had tuned a turboprop recently to have proper torque and RPM factors, and now the spoolup is way off, much slower).


I would be greatful for any input.



Bill
LHC

[Milton Shupe]

Hi Bill,

Ron Freimuth wrote an explanation of the effect of many aircraft.cfg parameter. i will send you a copy.

In it, he says this:

"[TurbineEngineData]
fuel_flow_gain=0.004 << Affects spool up rate by changing fuel controller gain"

And later, says this:

"inlet_area=9.80 << Set near or 10% above real turbine inlet area to
start. Higher values increase ram drag, less net thrust at high speeds

rated_N2_rpm = 12250 << can be left at 29920
static_thrust= 17000 << Set to get rated thrust at rated SL N1
This may be lower or higher than actual TO rating,
full throttle usually sets higher than rated TO thrust"

Now, in the .air file, table 1501 there is a engine turbine section with a parameters called "Spool up Rate".

You might try that. If you do not have that table, you can copy paste it from the Default KA 350.

[Lionheart]

Many thanks Milton!

I am off to read through this.

:ernae:


Bill

[Bjoern]

Milton, this sounds very interesting!


Any chance to get your hands on a public copy of that document?

[Milton Shupe]

Milton, this sounds very interesting!


Any chance to get your hands on a public copy of that document?

Bjoern, :wavey:

Yes, you can get this and a lot more at Herve's site:

http://pagesperso-orange.fr/hsors/index.html

[Bjoern]

Bookmarked.

Thanks, Milton!