Calculating Polar in See You, Which Numbers?

[[email protected]]

I am working on a new polar for my Silent-IN in See You. I have the data from Alisport, but the question that I have is which numbers to plug in to the See You Polar tool.

I have tried several different sets and get significantly different a. b. c. numbers in See You.

Any guidance on which pairs of numbers, speed plus sink rate would be helpful.

Min sink? Best L/D?, .............

After you use the tool, it defaults to 100, 120, 150 kph. This might be high for my lower performance bird.

Thanks

Kevin

[[email protected]]

On Tuesday, March 4, 2014 3:01:18 PM UTC-5, wrote:
> I am working on a new polar for my Silent-IN in See You. I have the data from Alisport, but the question that I have is which numbers to plug in to the See You Polar tool.
>
>
>
> I have tried several different sets and get significantly different a. b. c. numbers in See You.
>
>
>
> Any guidance on which pairs of numbers, speed plus sink rate would be helpful.
>
>
>
> Min sink? Best L/D?, .............
>
>
>
> After you use the tool, it defaults to 100, 120, 150 kph. This might be high for my lower performance bird.
>
>
>
> Thanks
>
>
>
> Kevin

Hi, Kevin,

don't go below the best l/d speed for your low number. Try putting together
a table of sink vs. speed in a spreadsheet, and calculate sink rate from a,b,c
and compare. Generally you'll do best with a low number around best l/d,
a high number around the fastest you'll fly, and the middle one in between.
I'll see if I can concoct a sample Google spreadsheet that shows how to do this.

Matt

[Bryan Searle]

At 20:01 04 March 2014, wrote:
>I am working on a new polar for my Silent-IN in See You. I have the data
>from Alisport, but the question that I have is which numbers to plug in
to
>the See You Polar tool.
>
>I have tried several different sets and get significantly different a. b.
>c. numbers in See You.
>
>Any guidance on which pairs of numbers, speed plus sink rate would be
>helpful.
>
>Min sink? Best L/D?, .............
>
>After you use the tool, it defaults to 100, 120, 150 kph. This might be
>high for my lower performance bird.
>
>Thanks
>
>Kevin
>

This is what I use for the Silent, using these Paul Remde tools:
http://www.cumulus-soaring.com/polars.htm

* LK8000 polar for: Silent2 Targa - 285kg AUW
* MassDryGross[kg], MaxWaterBallast[liters], Speed1[km/h], Sink1[m/s],
Speed2, Sink2, Speed3, Sink3, WingArea[m2]
285, 0, 92.0, -0.64, 146.0, -1.48, 200.0, -3.24, 8.9

* SEEYOU:
* 1.591
* -2.238
* 1.351

*Results from LK8000-V4 in simulate mode:

*Speed Efficiency Results Efficiency (Silent data)

* 90 39.6 40.0
* 95 39.6 39.6
* 100 39.9 38.5
* 105 39.7 37.5
* 110 39.2 37.0
* 115 37.8 36.5
* 120 37.0 35.0
* 125 35.0 34.0
* 130 34.0 33.0
* 135 31.9 32.0
* 140 30.9 30.0
* 145 28.9 28.5
* 150 27.0 27.0
* 155 26.1 26.5
* 160 25.3 25.0
* 165 24.4 24.0
* 170 22.9 22.0
* 175 21.5 21.5
* 180 20.6 20.0

Enjoy... Bryan

[[email protected]]

Thanks Matt,

Makes sense.

Kevin

[[email protected]]

> >I am working on a new polar for my Silent-IN in See You. I have the data

Thanks Bryan,

I will look over what you have, but I am flying the little brother to your bird, 12 meter 31-1.

Kevin

[[email protected]]

On Wednesday, March 5, 2014 5:44:00 AM UTC-5, wrote:
> > >I am working on a new polar for my Silent-IN in See You. I have the data
>
>
>
> Thanks Bryan,
>
>
>
> I will look over what you have, but I am flying the little brother to your bird, 12 meter 31-1.
>
>
>
> Kevin

Here's my spreadsheet:
https://docs.google.com/spreadsheet/ccc?key=0Arr0nA3RtG6IdDFQZUV0Q244LXhsS20yLWRPLTlZU Wc&usp=sharing

It calculates a, b, and c for you. Copy and paste it to your own
spreadsheet and you can play with the numbers.

[dhaluza]

You don't need to go below best L/D speed if all you want to do is cruise. But if you want to calculate netto, you will need the polar to be accurate at min sink too.

On Tuesday, March 4, 2014 11:12:24 PM UTC-5, wrote:
> On Tuesday, March 4, 2014 3:01:18 PM UTC-5, wrote:
>
> > I am working on a new polar for my Silent-IN in See You. I have the data from Alisport, but the question that I have is which numbers to plug in to the See You Polar tool.
>
> >
>
> >
>
> >
>
> > I have tried several different sets and get significantly different a. b. c. numbers in See You.
>
> >
>
> >
>
> >
>
> > Any guidance on which pairs of numbers, speed plus sink rate would be helpful.
>
> >
>
> >
>
> >
>
> > Min sink? Best L/D?, .............
>
> >
>
> >
>
> >
>
> > After you use the tool, it defaults to 100, 120, 150 kph. This might be high for my lower performance bird.
>
> >
>
> >
>
> >
>
> > Thanks
>
> >
>
> >
>
> >
>
> > Kevin
>
>
>
> Hi, Kevin,
>
>
>
> don't go below the best l/d speed for your low number. Try putting together
>
> a table of sink vs. speed in a spreadsheet, and calculate sink rate from a,b,c
>
> and compare. Generally you'll do best with a low number around best l/d,
>
> a high number around the fastest you'll fly, and the middle one in between.
>
> I'll see if I can concoct a sample Google spreadsheet that shows how to do this.
>
>
>
> Matt