XFOIL
Encyclopedia
XFOIL is an interactive program for the design and analysis of subsonic isolated airfoil
s. 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.
project in the 1980s. It was further developed in collaboration with Harold Youngren. The current version is 6.9. It has not been actively maintained since 2001. Despite its vintage, it is still widely used.
XFOIL is written in FORTRAN
.
.
An unrelated program called JavaFoil may be used for similar analysis. It is written in Java
.
Airfoil
An airfoil or aerofoil is the shape of a wing or blade or sail as seen in cross-section....
s. Given the coordinates specifying the shape of a 2D airfoil, Reynolds and Mach numbers
Mach number
Mach number is the speed of an object moving through air, or any other fluid substance, divided by the speed of sound as it is in that substance for its particular physical conditions, including those of temperature and pressure...
, XFOIL can calculate the pressure distribution on the airfoil and hence lift
Lift (force)
A fluid flowing past the surface of a body exerts a surface force on it. Lift is the component of this force that is perpendicular to the oncoming flow direction. It contrasts with the drag force, which is the component of the surface force parallel to the flow direction...
and drag characteristics. The program also allows inverse design - it will vary an airfoil shape to achieve the desired parameters.
History
XFOIL was first developed by Mark Drela at MIT as a design tool for the MIT DaedalusMIT Daedalus
The MIT Aeronautics and Astronautics Department's Daedalus was a human-powered aircraft that, on 23 April 1988, flew a distance of 71.5 mi in 3 hours, 54 minutes, from Iraklion on the island of Crete to the island of Santorini...
project in the 1980s. It was further developed in collaboration with Harold Youngren. The current version is 6.9. It has not been actively maintained since 2001. Despite its vintage, it is still widely used.
XFOIL is written in FORTRAN
Fortran
Fortran is a general-purpose, procedural, imperative programming language that is especially suited to numeric computation and scientific computing...
.
Similar Programs
A successor to XFOIL called XFLR is actively maintained, principally for use on model aircraft design. It is written in C++C++
C++ is a statically typed, free-form, multi-paradigm, compiled, general-purpose programming language. It is regarded as an intermediate-level language, as it comprises a combination of both high-level and low-level language features. It was developed by Bjarne Stroustrup starting in 1979 at Bell...
.
An unrelated program called JavaFoil may be used for similar analysis. It is written in Java
Java (programming language)
Java is a programming language originally developed by James Gosling at Sun Microsystems and released in 1995 as a core component of Sun Microsystems' Java platform. The language derives much of its syntax from C and C++ but has a simpler object model and fewer low-level facilities...
.