XFOIL is an interactive program for the design and analysis of subsonic isolated airfoils. Given the coordinates specifying the shape of a 2D airfoil, Reynolds and Mach numbers, XFOIL can calculate the pressure distribution on the airfoil and hence lift and drag characteristics. The program also allows inverse design - it will vary an airfoil shape to achieve the desired parameters. It is released under the GNU GPL.

History

XFOIL was first developed by Mark Drela at MIT as a design tool for the MIT Daedalus project in the 1980s.^[1] It was further developed in collaboration with Harold Youngren. The current version is 6.99, released in December 2013. Despite its vintage, it is still widely used.^[2]

XFOIL is written in FORTRAN.

Similar software

• Xfoil for matlab is a port of the original XFOIL code to MATLAB.^[3]
• mfoil is a MATLAB script that uses almost the same physical models as XFOIL, but is it not based on XFOIL. It also available as a Python script.^[4]
• JavaFoil is an independent airfoil analysis software written in Java.^[5]
• XFLR5 is an analysis tool for airfoils, wings and planes operating at low Reynolds Numbers, that has implemented XFOIL's Direct and Inverse analysis capabilities.^[6]
• QBlade implements XFOIL via XFLR5 for use in wind turbine design.
• OpenVSP is a parametric aircraft geometry and aerodynamic analysis tool supported by NASA.