How can I analyse the performance of an airfoil with Winfoil?

Airfoil Analysis

Winfoil has the capability to import airfoil polar data in PEF (Performance Exchange Format). Martin Hepperle has written a program called JavaFoil ( ) which has the capability to analyse any airfoil for a given Reynolds number, angle of attack range and flap deflection. Comparisons with the UIUC wind tunnel tests on airfoils for model aircraft are very favourable which makes Martin's JavaFoil program very useful for Model Aircraft design.

Shown below is a comparison between JavaFoil and the UIUC wind tunnel tests;

The results were for a Reynolds number of 102600 at higher reynolds numbers the results were closer.
Overall the results are accurate enough for model aircraft design and good alternative to expensive Wind Tunnel testing.

The following outlines the steps required to perform an airfoil analysis using JavaFoil and how to import the data into Winfoil. Please note this this functionality is only available in the registered version of Winfoil. To find out how to register please see the Purchase Page.

1. Open the Airfoil List Screen by either clicking on the Airfoil List toolbar button or selecting Airfoil List from the File Menu.

2. Click on the Airfoil you wish to analyse then click on the Coordinates tab.

3. Click on the Eppler 100 radio button below the coordinates. You should now be viewing the Airfoil Coordinates tab as shown below;

4. Start JavaFoil. You must have installed this program prior to this step.

5. Switch back to Winfoil and right click with your mouse over the coordinates list. You will get a popup menu which you can then select with the left mouse button. This action will copy the coordinates to the clipboard.

6. Switch back to JavaFoil.

7. Click with your mouse into the coordinates box and press the CTRL V keys to to paste the coordinates from the clipboard into the JavaFoil program shown below. Next click on the Update View button.

8. Fill in the name of the airfoil then click on the Polar Tab

9. Enter the required values for the following fields

  • first Reynolds Number

  • last Reynolds Number

  • Reynolds number step

  • Surface Finish

  • Transition strip location on upper surface (T.U)

  • Transition strip location on lower surface (T.L)
  • first Angle of Attack

  • last Angle of Attack
  • Angle of Attack step

You must then click on the Analyse It! button.

10. Next click on the Save button and select the required directory and enter the name of the file with the .pef extensions program prior to this step.

11. You can now switch back to Winfoil to Import the data. You must now click on the Import Toolbar button or select Import from the File Menu. You must then select the JavaFoil PEF format import option and click on the Ok button as shown below;

You can then select the file and import it. During the import process you will be asked to select an airfoil to import the data for. You must select the airfoil which you ran the analysis for. You can do this by selecting it from the dropdown list of available airfoils. After you have chosen the airfoil you must click on the ok button to proceed.

Once complete you can then view the polars and lift/drag graphs by clicking on the tabs in the the airfoil list screen.

To compare airfoil performance please see Airfoil Comparison