Frequently Asked Questions

Design Components [Click to hide]

Winfoil is configured using a number of parameters to allow the user to create new aircraft configurations, new design components, to customise the drag breakdown analysis and to enter or modify drag coefficients for aircraft items.

The following outlines the steps required to add a component to the Tandem Wing Aircraft Configuration.
We will be adding a new wing component. Please note this this functionality is only available in the registered version of Winfoil. To find out how to register please see the Registration Page.

1. Open the Preferences screen from the File Preferences Menu.

2. Click on the Advanced button on the lower left.

3. This action will open the Parameter Maintenance screen shown below.

4. Click on the Search button.

5. This action will open the Search screen. Click on the Design Components entry and then click on the Ok button.

6. We want to add a new wing component, so we click on the New button on the lower right and this will then open the Parameter Type Maintenance screen as shown below.

7.Enter the new component Short Description and Description. You should also take note of the Parameter No. which is automatically assigned. In this case it is 12. This number will be used in the next step.

8. Click on the Save button to create the component.You will then be returned to Parameter Maintenance screen.

9. Click on the Search button in the Parameter Maintenance Screen. Click on the Component Grouping entry in the Search screen and then click on the Ok button.

10. In the Parameter Maintenance Screen select the All Wing entry in the list in the lower section of the screen and then click on the Edit button. In the Data field add the Number for the new component obtained from step 7 above. In this case it was 12. Each entry is delimited by a special character. Winfoil determines this character depending on the regional settings of the PC on which it is installed. In most English speaking countries it is a comma in other countries it will be a pipe character (|). This is to ensure that the delimiter is not confused with any numeric formatting character as a number of countries use a comma to represent a decimal point. An example is shown below;

11. Repeat step 11 for the following items for the Component Grouping Parameter;
All Wing Components

12. Click on the Search button in the Parameter Maintenance screen and select the Aircraft Configuration item and click on the Ok button.

13. Select the Tandem Wing Configuration in the List in the lower half of the screen and click on the Edit button. Add the item number to the Data and Data Extra fields as shown below. Note that a delimiter is used to separate the values.In this case it is a comma. The delimiter is the same for all parameters it will either be a comma (,) or a pipe (|). The Data Extra Field is used to indicate that the Aspect Ratio must be entered in the Drag Breakdown. This is required for any lifting wing surface. As this is a tandem wing both wings are contributing lift just like a Canard design. Then click on the Save button.

14. Click on the Search button in the Parameter Maintenance screen and select the Drag Items entry and click on the Ok button.

15. Click on the New button on the lower right of this screen to create a new drag item and to link it to the new design component we entered in step 6 above. In this screen enter the Short Description, Description and component number which is 12 for this item( from step 6). In this case it is a coincidence that the component number and the new drag item number are the same normally this will not be the case as this is automatically generated by Winfoil. Shown below is the new drag item. Click on the Save button.

16. Click on the Close button on the Parameter Maintenance Screen then Canecl button on the Winfoil Preferences Screen. Close the Design Screen if open and then open it again. The parameters will now be reloaded. You will now be able to add a Wing2 component to a Tandem Wing design and the Wing2 component will show up in the Drag Breakdown screen. You may need to click on the Default button in the Drag Breakdown tab to recreate the drag breakdown so that the new drag item is created.

To delete a drag item from the configuration, select the Aircraft Configuration item in the Parameter Maintenance screen and then edit the Tandem Wing configuration and remove the item number from the Data and Data Extra fields. To remove the Horizontal Tail ite, look up the number which is for this component 8. Remove item 8 from the Data and Data Extra fields for the Tandem Wing Configuration. An Example is shown below.

You can see that item 8 has been removed. You will then need to click on the Default button in the Drag Breakdown tab to recreate the drag breakdown so that Horizontal Tail Item is removed.

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Design Components - Adding Fuselage Formers [Click to hide]

Winfoil is configured using a number of parameters to allow the user to create new aircraft component types. The following article outlines the steps required to add a new Fuselage Former Component.

Please note this this functionality is only available in the registered version of Winfoil. To find out how to register please see theRegistration Page.

1. Open the Preferences screen from the File Preferences Menu./p>

2. Click on the Advanced button on the lower left.

3. This action will open the Parameter Maintenance screen shown below.

4. Click on the Search button.

5. This action will open the Search screen. Click on the Design Components entry and then click on the Ok button.

6. We want to add a new fuselage component, so we click on the New button on the lower right and this will then open the Parameter Type Maintenance screen as shown below.

7.Enter the new component Short Description and Description. You should also take note of the Parameter No. which is automatically assigned. In this case it is 15. This number will be used in the next step.

8. Click on the Save button to create the component.You will then be returned to Parameter Maintenance screen.

9. Click on the Search button in the Parameter Maintenance Screen. Click on the Component Grouping entry in the Search screen and then click on the Ok button.

10. In the Parameter Maintenance Screen select the Fuselage Components entry in the list in the lower section of the screen and then click on the Edit button. In the Data field add the Number for the new component obtained from step 7 above. In this case it was 15. Each entry is delimited by a special character. Winfoil determines this character depending on the regional settings of the PC on which it is installed. In most English speaking countries it is a comma in other countries it will be a pipe character (|). This is to ensure that the delimiter is not confused with any numeric formatting character as a number of countries use a comma to represent a decimal point. An example is shown below;

11. Repeat step 11 for the following items for the Component Grouping Parameter;
All Fuselage Comps and All components.

Now when you add a design item in the Design List screen the Fuselage Former 7 will appear in the dropdown list of Types.

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Import DXF [Click to hide]

Winfoil automatically formats numbers according to your Regional Number Format Settings in Control Panel. A number of Windows programs do not do this and always treat numbers as being in United States or English format. An option is provided in Winfoil to automatically convert all DXF files to format numbers in English or US format. To do this;
1.Go into the Preferences screen from the File Preferences menu.
2.Click on the DXF Export Tab.
3.Check the US English Number Format Checkbox.
4.Click on the OK button below.
Try the export again and it should be ok.

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Updates [Click to hide]

Whenever Winfoil is started it will check if it can access the Winfoil updates using your internet connection. If any updates are found then an update popup screen will be displayed prompting you to accept a download. Once you have downloaded the update you will be required to select a directory where Winfoil was installed. After selecting the directory you will need to click on the Next button to apply the update. There is no need to exit Winfoil during the update process as it will automatically shutdown Winfoil then restart it after the update is complete.

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Airfoil Analysis [Click to hide]

Winfoil has the capability to import airfoil polar data in PEF (Performance Exchange Format). Martin Hepperle has written a program called JavaFoil (http://www.mh-aerotools.de/ ) 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 Registration 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.

9. Next click on the Save button and select the required directory and enter the name of the file with the .pef extension.

10. 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

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Airfoil Comparison [Click to hide]

This feature is accessed from the Compare button on the Airfoil Polar Graph Tab or from the Lift Graph Tab on the Airfoil List screen.

This feature provides the ability to ;

• Select Reynolds numbers for Polar and Lift Graphs for a selected Airfoil.
• Compare an Airfoil against another selected Airfoil and Reynolds number.
• Compare an Airfoil against a number of airfoils with the data for the same Reynolds number.

When the Compare button is pressed the Graph Properties screen will displayed as shown below;

To select one or multiple Reynolds numbers to graph for either the Polar or Lift Graph;

Click on one or more Reynolds numbers in the Select Reynolds Number list and then click on the Ok button. Do not click on the Compare check box if you wish to select more than one Reynolds number.

To compare with other Airfoils;

Click on the Compare check box. Click on the Show all Airfoils to select an Airfoil from the list of all Airfoils in the database with performance data. If you choose this option you must select an Airfoil for the comparison and a Reynolds number. Click on the Show Airfoils option to select an Airfoil for comparison which has data that matches the selected Reynolds number. You must then select an Airfoil then a Reynolds number. If you also click on the Cycle checkbox then there is no need to select an Airfoil for the comparison or Reynolds number. Winfoil will automatically cycle through each matching airfoil. The Pause textbox is the delay in seconds between redrawing the graph for each Airfoil comparison.

If the Cycle checkbox is selected then when the Ok button is clicked and the Graph is displayed the an additional toolbar will be displayed to control the cycle.

The buttons on this toolbar perform the following actions;

Pause	Pauses the cycle to allow the user to Save the displayed graph as a bitmap or Print the graph or take a note of the airfoils being compared.
Cycle	Restarts the cycle process.
End	Ends the cycle process and returns to the Graph screen. You must click on this button so that you can continue using Winfoil and to exit this special mode.
Save	This button is used to save the currently displayed graph as a bitmap. This button is only enabled after the Pause button is pressed.
Print	This button is used to print the currently displayed graph. This button is only enabled after the Pause button is pressed.

This Winfoil feature was used to perform the comparison of UIUC wind tunnel test data and Martin Hepperle's CalcFoil program. See Airfoil Analysis

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