This page performs translation of airfoil input file formats.
Some airfoil analysis programs define an airfoil with x and y coordinates starting from the trailing edge, looping over the upper surface to the leading edge, then over the lower surface back to the trailing edge. This two column format is used by many CFD programs. PANDA 1.x uses a simple 3 column format that starts at the leading edge and proceeds to the trailing edge with x, y_upper, and y_lower. Airfoils that are not defined with the same number of upper and lower surface points, or with different upper and lower surface x-values can be difficult to represent in the format of PANDA 1.x.
The applet below does a very simple translation, linearly interpolating the lower surface coordinates if necessary to approximate the section in 3-column format. Paste the coordinates into the appropriate field below (the left text area if 2-column format, the right area if the coordinates are available in the 3-column format), then click the desired button to translate. You may then copy the translated field (use the keyboard shortcut CTRL + c to copy) and paste it into an input file for the airfoil program. Note that you may need to shift the section to place the leading edge at x = 0, yu = yl = 0, and you may need to replace numbers such as 2.05E-04 with 0.000205 before some programs will parse them correctly.
An alternate approach for converting 2 column data into PANDA 1.x input format that may work better in some applications, but is a bit involved. You can read a 2 column airfoil into excel and create two symmetrical airfoils -- one with the correct upper surface and one with the correct lower surface. (This involves a bit of copying and pasting and resorting, but can be done quickly.) Save each of these airfoils in 3 column format as a separate text file. Read each one into PANDA, and save the coordinates from PANDA. You will now have two symmetric airfoils with the same x/c values. Copy the upper surface and lower surface coordinates into excel to create a single airfoil for PANDA.
