Glider Polar Data

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igoskyward
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Glider Polar Data

Post by igoskyward » Fri Mar 02, 2018 3:22 pm

I am looking to export the glider polar data for use in an external PDA, such as XCSoar. Although some data is available elsewhere on the net, it may not be exactly the same numbers used for the Condor2 gliders. Is there a way to extract the actual polar data used in the planes .pol files (i.e. Antares18s.pol )? My current text editors aren't able to extract useful data as it only shows "gibberish"... If direct extraction from .pol files isn't possible, perhaps as an alternative could the development team make that polar data available in a separate file?

Tom
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Re: Glider Polar Data

Post by Tom » Fri Mar 02, 2018 4:28 pm

The Problem is as far as I remember at least one of the polars is under an NDA and some other manufacturer's who provided data asked us not to share it. Maybe OXO can help with explaining more on that side of things.
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sadatoni
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Re: Glider Polar Data

Post by sadatoni » Sat Mar 03, 2018 4:53 pm

The only thing I would suggest is to make your own .plr file and import that into XCSoar. The format is (ASW-28 example) using the in-game polar char to figure out the numbers:

* ASW28 WinPilot POLAR file generated with Condor2Nav
*
* MassDryGross[kg], MaxWaterBallast[liters], Speed1[km/h], Sink1[m/s], Speed2, Sink2, Speed3, Sink3
268,180,77,-0.572,129,-1.021,185,-2.9198

The Manual states for the speed/sink pairs:

• Speed in km/h for first measurement point, (usually minimum
sink speed).
• Sink rate in m/s for first measurement point.
• Speed in km/h for second measurement point, (usually best
glide speed).
• Sink rate in m/s for second measurement point.
• Speed in km/h for third measurement point, (usually max
manoeuvring speed).
N5503T CN(0OU)

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John Ferguson

mada2000
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Re: Glider Polar Data

Post by mada2000 » Sat Mar 03, 2018 6:30 pm

igoskyward wrote:
Fri Mar 02, 2018 3:22 pm
I am looking to export the glider polar data for use in an external PDA, such as XCSoar. Although some data is available elsewhere on the net, it may not be exactly the same numbers used for the Condor2 gliders. Is there a way to extract the actual polar data used in the planes .pol files (i.e. Antares18s.pol )? My current text editors aren't able to extract useful data as it only shows "gibberish"... If direct extraction from .pol files isn't possible, perhaps as an alternative could the development team make that polar data available in a separate file?
Here you are :-)
Made by me with accuracy ... enough for me :)
https://drive.google.com/open?id=1uLfg5 ... 9jmfsYDP8l
Last edited by mada2000 on Mon Mar 05, 2018 8:48 am, edited 1 time in total.

igoskyward
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Re: Glider Polar Data

Post by igoskyward » Sat Mar 03, 2018 8:49 pm

Thanks guys, I appreciate all the input. I wasn't aware of the Non Disclosure Agreement, but now I do have something to work with.

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Bre901
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Re: Glider Polar Data

Post by Bre901 » Mon Jul 02, 2018 3:41 pm

Since mada2000 computed his polars for XCSoar (see above), new gliders have been available and some data have changed for existing gliders (namely fixed ballast).

I have computed polars for all the gliders available today in Condor2 (except SwiftS1, GrunauBaby and SG38), with or without fixed ballast or 2nd pilot.

No need to fiddle with ballast settings in XCSoar any more : for a given ballast setting XCSoar and Condor have the same wing loading

The accuracy is quite good (mean square deviation < 1.5%), except for the high speed part of the Duo-Discus polar (see below)

The files are available there : https://drive.google.com/open?id=1PWbcP ... 2P2n84Zkms

As always, I strongly suggest reading the README.txt.

As I have developed a semi-automatic procedure to generate the polars, I shall release them for new gliders when they become available.

Upon request, I could also generate polars for Condor1 gliders (for plane pack #1, you will have to provide some data as I don't have it)
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CN : MPT

tiberius
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Re: Glider Polar Data

Post by tiberius » Wed Jul 04, 2018 9:53 am

Nice work, thank you. Makes you realise just how good the Diane 2 is!!
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Mikko
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Re: Glider Polar Data

Post by Mikko » Thu Jul 05, 2018 9:16 am

Am I missing something here? Diana 2 has the same polar as JS1 18m, Antares clearly better than JS1? Doesn't quite make sense to me.

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OXO
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Re: Glider Polar Data

Post by OXO » Thu Jul 05, 2018 9:21 am

Mikko wrote:
Thu Jul 05, 2018 9:16 am
Am I missing something here? Diana 2 has the same polar as JS1 18m, Antares clearly better than JS1? Doesn't quite make sense to me.

Higher wingloading for the Diana.

Why can't the Antares be better than JS-1? We have only used the published data. JS-1 is better at low speed, Antares is better at high speed. Again, wingloadings are different.
Chris Wedgwood,
Condor Team

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dgtfer
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Re: Glider Polar Data

Post by dgtfer » Fri Jul 06, 2018 10:40 am

OXO wrote:
Thu Jul 05, 2018 9:21 am
Why can't the Antares be better than JS-1?
Both DAEC indexes and competition results seem to indicate the opposite!
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OXO
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Re: Glider Polar Data

Post by OXO » Fri Jul 06, 2018 1:34 pm

dgtfer wrote:
Fri Jul 06, 2018 10:40 am
OXO wrote:
Thu Jul 05, 2018 9:21 am
Why can't the Antares be better than JS-1?
Both DAEC indexes and competition results seem to indicate the opposite!
Do I need to explain why those things are not a reliable way to set the polar?
Chris Wedgwood,
Condor Team

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dgtfer
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Re: Glider Polar Data

Post by dgtfer » Fri Jul 06, 2018 7:51 pm

Of course not, and your choice is the only possible!
Since Dick Jonhson's death, independent and accurate datas on real performances are not published.
But does it means that the "official" polar curves given by the planes manufacturers are not always perfectly genuine, while the technical board of Daec knows the results of Akaflieg tests?...
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dpluigi
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Re: Glider Polar Data

Post by dpluigi » Fri Jul 06, 2018 11:44 pm

Thank you for posting these updated Polar files. I started using Mada2000's polar files until I realized they had typos and inaccuracies, then I started measuring them again using Condor2 polar graph. You beat me to it before I could go around doing them all. Selecting the XCSoar ballast so that its wing loading matched that of condor 2 (i.e. guessing excess water ballast to make up the difference between fixed and or extra pilot) was always a little crude and half-assed before a task. You helped us take the guesswork out of the pre-flight setup. Wll you add these files with you next version of CaToCa?

Thank you again Marc forboth these polar files and for your application CoTaCo, which so useful in generating the XCSoare task files.

Donat
CN 269
Bre901 wrote:
Mon Jul 02, 2018 3:41 pm
Since mada2000 computed his polars for XCSoar (see above), new gliders have been available and some data have changed for existing gliders (namely fixed ballast).

I have computed polars for all the gliders available today in Condor2 (except SwiftS1, GrunauBaby and SG38), with or without fixed ballast or 2nd pilot.

No need to fiddle with ballast settings in XCSoar any more : for a given ballast setting XCSoar and Condor have the same wing loading

The accuracy is quite good (mean square deviation < 1.5%), except for the high speed part of the Duo-Discus polar (see below)

The files are available there : https://drive.google.com/open?id=1PWbcP ... 2P2n84Zkms

As always, I strongly suggest reading the README.txt.

As I have developed a semi-automatic procedure to generate the polars, I shall release them for new gliders when they become available.

Upon request, I could also generate polars for Condor1 gliders (for plane pack #1, you will have to provide some data as I don't have it)
ImageImage

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Bre901
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Re: Glider Polar Data

Post by Bre901 » Tue Sep 18, 2018 8:02 am

Following the release of the Ventus3, I have updated the polar set, it is available for download :
https://drive.google.com/open?id=13_8Cf ... L5g3ZO2Ug-

The set is complete with all the previous (unchanged) polars.
As usually, taking at look at the README.txt is recommended
Last edited by Bre901 on Sat Jan 25, 2020 8:33 am, edited 1 time in total.
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Crakob
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Re: Glider Polar Data

Post by Crakob » Tue Sep 25, 2018 9:45 am

Sorry for asking.

is there no V3 15m FXB ?

Christian
CRAKOB = CRA

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