XFLR5

XFLR5

XFLR5 is a free and open-source program for the aerodynamic analysis of airfoils, wings and planes operating at low Reynolds numbers, such as model aircraft. It combines XFoil airfoil analysis with Lifting Line Theory, the Vortex Lattice Method and a 3D panel method. It can perform the following tasks:

• Analysis of the lift, drag and moments of any wing or complete plane, including a wide range of lift, drag and moment coefficients.

XFLR5 enables users to quickly estimate the aerodynamic performance and stability of airfoils, wings and model aircraft designs.

• Analysis of the static stability of the aircraft, including the neutral point, static margin and stability derivatives.

• Analysis of the dynamic stability of the aircraft, including the longitudinal and lateral natural modes and their eigenvalues.

• Analysis of the trim of the aircraft, including trim speed, trim angle of attack and trim lift coefficient.

• Time response of the aircraft to perturbations and to control inputs, as open-loop and forced responses.

• Direct analysis of airfoils with XFoil, producing polars of lift, drag and moment for chosen Reynolds and Mach numbers.

• Inverse airfoil design with the full and mixed inverse methods inherited from XFoil.

• Airfoil geometry design, including thickness and camber changes, flaps and the generation of NACA airfoils.

• Batch analysis of airfoils over ranges of Reynolds numbers.

• Analysis of the effects of changes in aircraft mass, CG location and control positions on stability and trim.

• Choice of analysis method for each polar: Lifting Line Theory, Vortex Lattice Method or 3D panel method.

• A wide range of graphical outputs which can be used to visualize the performance and stability of the aircraft.

• An interactive user interface, including a 3D viewer for the visualization of the aircraft geometry and results.

• Design of wings and planes with a main wing, elevator, fin and an optional fuselage body.

• Sequential analyses over ranges of angles of attack or speeds, with the results stored as polars and operating points.

• Export of graph curves to text or CSV files for processing in spreadsheets.

• The ability to export airfoils as coordinate files usable in XFOIL and other programs, and planes to AVL.

XFLR5 is a free and versatile program for the aerodynamic analysis of airfoils, wings and planes. It is released under the GNU GPL for Windows, macOS and Linux. The project was closed in 2026 with no further releases, and its author continues the work in flow5, the successor program. As a hobbyist tool provided without guarantee, it is best suited to model aircraft design and education.