Performance

Parameters used in the calculation of aircraft performance.

Max. Propeller Efficiency is used to calculate Power Available. The typical values are 0.75 (75%) to 0.85 (85%).

Max. Lift Coefficient is used to calculate the stall speed. This varies according to the airfoil selected for the design. For non flapped wings this is typically 1.2 to 1.4. For flapped wings this can be in the order of 2.0 to as much as 3.0 where leading edge slats and double slotted flaps are used.

Database

File name of the database. This setting tells Winfoil where the database file WINFOIL.MDB is located. This enables the database file to be shared over a network for multi user use. By default Winfoil will look for the database in the directory where it was installed if this is not set otherwise it will use the location specified. To select a different file click on the Browse button. If the database cannot be found then you will be prompted to select a valid V2.2 database file. If a valid database is selected this setting will be updated.

Printing

Printer calibration may be necessary due to the age of the printer or some printer driver inaccuracy. Winfoil V2.2 provides the ability to apply both vertical and horizontal adjustments to Rib and Wing,Fuselage Plan printing.

Correction factors for rib and airfoil printing. These are normally set to 1. To increase the length of a rib if the printed output is too short, divide the measured length by the required length. Use this value for the horizontal correction factor. To decrease the length of a rib, divide the measured length by the required length. Use this value for the horizontal correction factor. Similarly for the vertical size enter the appropriate correction factor if incorrect.

Before changing the correction factors you should do a Test Print. Select the measurement units either Inches or Millimetres then click on the Test Print button. This action will cause a special test page to be printed. This page has a horizontal line and a vertical line. If Inches was the selected measurement units then each line will marked by one inch intervals. If Millimetres was selected then each line will be marked by 10 millimetre intervals. You will need to measure these to ensure that the intervals are the correct length. If not then enter the appropriate correction factor in the Preferences screen and reprint. Repeat this process until it is correct.

Example;

Examining the Vertical Line in the Test Print we find that;

1 Interval (10 millimetres) is actually 8 millimetres.

Therefore we need to correct the printing in the vertical axis as it is 2 millimetres short.

To derive the correction factor;

Correction factor = Required length divided by test print length

1.25 = 10 / 8

Therefore we must enter 1.25 as the vertical correction factor.

Click on the OK button once set.

DXF Export

Accuracy of numeric values in DXF exported data. This value is used to format the numbers produced by the DXF export. The default is 4.

For Example;

4 decimal places = 1.0000

2 decimal places = 1.00

The Use DOT Line Type checkbox is used in the DXF export for ribs and airfoils. If the CAD program you are using to import the DXF files does not support the DOT line type then you should uncheck this option. The DOT line type is used to plot the airfoil or rib datum line. If this option is unchecked then a Continuous line type will be used for the datum line.

The US English Number Format checkbox is used to force the DXF exported file to format all numbers as the English number format. There are a number of Windows CAD programs on the market which do not support international number formats. Winfoil exports numeric data in a format according to the Regional Settings for the PC on which it is run. You may need to check this option if the CAD program you are using to import the DXF file does not support International number formatting.

Tools

Additional programs which can be run from the Tools Menu. See Tools Tab for more detail.

Import/Export

This setting is used to specify the template Excel spreadsheet file used to export performance data from Winfoil. Winfoil establishes a DDE connection with Excel to export the data to the spreadsheet. You must have Excel installed on your computer for this function to work. If Excel cannot be found an error message will be displayed. The sample excel spreadsheet may be customised to your liking if required. To select a different file click on the Browse button.

A new option has been added to select a delimiter character for the export files. This option is required for some countries as numbers are formatted with commas for decimal points and the Winfoil default export delimiter is a comma. In Germany or France a character should be selected which does not represent a thousand seperator or a decimal point.

Other

This tab contains settings for the following settings.

Enable Half Span in Wing Design Screen

If this setting is enabled then the span entered in the Design Cad screen for wings will be the half span value. If not enabled then the span is the full span length.

Dimensions Default
Default length units for printing and creating designs can be selected here.

JavaFoil Parameters

This tab is used to set the JavaFoil Parameters for the airfoil analysis. To change the settings click on the Change button.