Forces on a Paraglider during a winch launch

3 Paraglider configurations,  Pilot using Trim-Speed, or Best-Glide  or Minimum-Sink

Top 3 are at 60 degree tow line angle

Below is 45 degree

 30 degree

and flat on the ground

With the cursor one controls the tension=tow force and the weight of the pilot = all up weight  in kg

 

 The tow line force in Cyan  in Newton

 And red top line is the Drag.

 Blue shows the forward component of the wing/pilot, same direction as the Drag.

And in blue we get the climb rate

 Green is the Lift component , vertical  to the forward speed

 Yellow  is the combined Lift + Drag Force counter acting the combined Tow + Weight

Black bottom number shows the all up weight in Newton


 

 

Want to  run the Applet on your computer and add your glider data

Java 1.4 has to be installed,  download from java.sun.com

Download the best.jar file into some new created directory.

mkdir C:\tmp\test ... for example

Use jar -xvf best.jar  or a zip utility to unzip the best.jar file.

  cd C:\tmp\test

   jar -xvf best.jar

  Copy from the appletcode the wingdata.xml and dtd file one higher up into your new created directory.

   cp appletcode\wingdata.* .

And start the code

C:\tmp\test>java appletcode/Winch/Forces/WinchForceApplet.class

How to add your own Wing Data Information into the wingdata.xml file.

Then modify the wingdata.xml file and add your glider data to it.

The wingdata.xml file format

  PolarCount can be 3 or 4 or 5 for the amount of polare points

The first point has to be the minimum sink point. Where the polare tangent is horizontal.

The next points have to points on the polare as the speed increases.

The last point is the top speed on the polare.

A point is defined by the speed in km/h   and a sinkvalue im m/s
 

The sample data provided is based on the info available from
http://parapente.para2000.free.fr/wings/index.html
The wingdata.xml file format
<Wing WingId="Effect38-3" Name="Effect38 3 Points" Span="9.93" MinSpeed="22" TrimSpeed="37">
<PolarData PointCount="3">
<PolarPoint Speed="30." Sink="-1.15" />
<PolarPoint Speed="36." Sink="-1.31" />
<PolarPoint Speed="50." Sink="-2.9" />
</PolarData>
</Wing>

WingId has to be unique, no 2 wings can have the same Id
Name can be anything you choose, a long string that explains a bit more
Span is the projected ( not the flat) wing span
MinSpeed would be stall speed
TrimSpeed is toggles up and no accellerator applied
PointCount can be 3 or 4 or 5 for the amount of polare points
The first point has to be the minimum sink point. Where the polare tangent is horizontal.
The next points have to points on the polare as the speed increases.
The last point is the top speed on the polare.
A point is defined by the speed in km/h and a sinkvalue im m/s

Polar data info you find at
http://www.para2000.org/wings/index.html

The code has also been integrated with T3D2

http://sourceforge.net/projects/t3d2

http://t3d2.sourceforge.net/




Known bugs :

Not very robust code, do not deviate and experiment with different input format.
The code will freeze up your computer.

5 point polare go wobbly, having dents, typical behaviour of a spline curve as the degree goes up


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