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View Full Version : FB energy bleed and instant turn rate charts



XyZspineZyX
03-24-2003, 07:55 AM
I performed a few tests and i used the measured parameters to build a few interesting charts. You can see the charts and read all about testing procedure and calculations here:

http://www.alexvoicu.home.ro/turning.html

Any comments, suggestions and new testing ideas are welcome.

--------------------
Alex "Bloodhound" Voicu

XyZspineZyX
03-24-2003, 07:55 AM
I performed a few tests and i used the measured parameters to build a few interesting charts. You can see the charts and read all about testing procedure and calculations here:

http://www.alexvoicu.home.ro/turning.html

Any comments, suggestions and new testing ideas are welcome.

--------------------
Alex "Bloodhound" Voicu

XyZspineZyX
03-24-2003, 08:07 AM
Interesting stuff... just a tip, the no cockpit view provides TAS down to the closest km/h. (numbers in the dial) That might help alleviate some of the errors you spoke of.

Cheers.

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XyZspineZyX
03-24-2003, 08:34 AM
As, you can see from the charts, i used TAS for my calculations. The most important errors are caused by the small banking variations during turning; i updated the page mentioning this type of errors.

Alex "Bloodhound" Voicu

XyZspineZyX
03-24-2003, 09:16 AM
You need to include the state of trim. Due to the fact that stickforces are modelled, when you pull back all the way on your joystick this represents maximum force being applied to the stick, but at high speeds the amount of control surface deflection you get at full force can vary depending upon how the elevator is trimmed. Since you are trying to ignore the pilots limitations I reccomend trimming maximum elevator up and retrying the test.

XyZspineZyX
03-24-2003, 10:39 AM
That's a very good idea. Thanks a lot.

XyZspineZyX
03-26-2003, 10:47 AM
Alex, have you read this?

http://www.simhq.com/simhq3/sims/air_combat/co-e_chase/

On your webpage you state:

"The absolute value of the energy bleed is useless; only comparative tests of 2 airplanes can lead us to a conclusion."

but in fact the rate for a given plane is useful by itself as it can be used to determine the speeds of most efficient enrgy transfer for that plane. Also note that when comparing two different planes, as one of your charts does, it is only useful for planes pulling the same G forces.

Your chart showing the 109K4 and LA7 energy bleeds seems to indicate the LA7 has efficient enrgy transfer down to a lower speed, and both have about the same upper speed of efficient energy transfer, but it is hard to know if this relationship holds true at all G forces and at all altitudes.

I'm not sure there is a practical way to get the energy transfer rate at different G forces for a given plane at a given altitude, but if there is that would be the most useful information of all. I feel that understanding the relative energy transfer characteristics of different planes at different altitudes and G forces is the key to formulating optimal dogfighting strategy for any given matchup.

XyZspineZyX
03-26-2003, 12:28 PM
It's a lot of subjective cobblers.

When it becomes possible to have a computer fly the real planes in a consistent atmospheric medium we'll know exactly what each warbird should fly like in a simulation. Until then we can have only approximations that will always be the subject of furious, and futile, debate. /i/smilies/16x16_smiley-happy.gif

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XyZspineZyX
03-26-2003, 03:39 PM
I think you have done a very good and informative job here. Info on this numbers is scarce and never so well presented and explained. Congratulations. Keep it up.

As one rarely flies with maximum trim I would suggest you stick to the centered trimmers and leave to the pilot the extrapolation via expierence.

Thanks for the good job. I have thought a hundred times to do something similar, but I lack the patience.



Kuikueg

michapma
06-23-2003, 01:59 PM
Just happened across this while digging for an old thread. Interesting? I'll have to look at it later. Even if the information is not decisive, I love to see this stuff instead of the usual *highly* subjective stuff.

Thanks for the work.

Mike

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Manifold Pressure sucks (http://www.avweb.com/news/columns/182081-1.html)
Those Marvelous Props (http://www.avweb.com/news/columns/182082-1.html)
Mixture Magic (http://www.avweb.com/news/columns/182084-1.html)
Putting It All Together (http://www.avweb.com/news/columns/182085-1.html)
Those Fire-Breathing Turbos (Part 1 of 6) (http://www.avweb.com/news/columns/182102-1.html)</td><td align="center">

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XyZspineZyX
06-23-2003, 04:31 PM
Thanks for taking the time!
Informative and useful imho.

I can only say (after looking at the last graph, especially) "thank you, Oleg, for getting rid of the trim-wheel trick (even if you kindofporkedit)"

those bat-turns with trim are pretty scary on that last graph /i/smilies/16x16_smiley-very-happy.gif

Thanks again Voicu
CG

XyZspineZyX
06-23-2003, 04:49 PM
A clear example of bat turns. Those that think trim on a slider doesn't work, should look at this.

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