Design and Test a Wing in XFLR5
See how airfoil shape controls lift, drag, and stall
Last reviewed: March 2026Overview
Every aircraft ever built started with the same question: what shape should the wing be? The answer depends on speed, altitude, payload, and a dozen other factors — and aerospace engineers use specialized software to find the best design.
XFLR5 is a free, open-source tool based on MIT's XFOIL code that lets you analyze airfoil shapes and wing designs. It's the same tool used by university design teams in AIAA competitions, and it runs on any laptop.
In this project, you'll analyze classic airfoils (like the NACA 2412 used on Cessnas), design your own wing planform, and discover how small changes in shape dramatically affect performance. By the end, you'll understand lift curves, drag polars, and stall behavior — the fundamental language of aerodynamics.
What You'll Learn
- ✓ Install and navigate XFLR5 for airfoil and wing analysis
- ✓ Understand lift coefficient, drag coefficient, and the lift-to-drag ratio
- ✓ Analyze how airfoil geometry affects aerodynamic performance
- ✓ Design a wing planform and evaluate its performance envelope
- ✓ Read and interpret aerodynamic plots (CL vs alpha, polar diagrams)
Step-by-Step Guide
Install XFLR5 and Load Airfoils
Download XFLR5 from the official site (free, Windows/Mac/Linux). Launch it and go to the Direct Foil Design module. Load the NACA 2412 airfoil from the built-in database — this is one of the most commonly used airfoils in general aviation.
Also load the NACA 0012 (symmetric) and NACA 4415 (high-lift) for comparison.
Run Airfoil Analysis
Switch to XFoil Direct Analysis mode. Set up a batch analysis: Reynolds number around 500,000 (typical for model aircraft) and angle of attack from -5° to 15° in 0.5° increments.
Run the analysis for all three airfoils. XFLR5 will calculate lift coefficient (CL), drag coefficient (CD), and moment coefficient (CM) at each angle.
Compare Airfoil Performance
Plot CL vs. angle of attack for all three airfoils on the same graph. Notice how the NACA 4415 generates more lift at low angles but stalls earlier, while the NACA 0012 is symmetric (zero lift at zero angle).
Plot the drag polar (CL vs. CD). Which airfoil has the best lift-to-drag ratio? At what angle of attack? This is the best glide condition — crucial for aircraft efficiency.
Design a Wing
Switch to the Wing and Plane Design module. Create a simple rectangular wing using your best-performing airfoil. Set the span, chord, and any taper or twist you want to experiment with.
Start with a 1-meter span, 15cm chord, rectangular wing. Then try adding taper (smaller chord at the tips) and washout (tips twisted to a lower angle) to see how these affect performance.
Analyze Wing Performance
Run the Lifting Line Theory (LLT) or Vortex Lattice Method (VLM) analysis on your wing. This calculates the full 3D aerodynamic performance including induced drag — the penalty you pay for having a finite-span wing.
Compare your rectangular wing to a tapered wing. How much does taper reduce induced drag? This is why almost every modern aircraft has tapered wings.
Document Your Design
Create a one-page design summary: your chosen airfoil, wing geometry, key performance numbers (max L/D, stall speed, CL_max), and the plots that justify your choices. This is exactly how real preliminary design reports are structured.
Career Connection
See how this project connects to real aerospace careers.
Aerospace Engineer →
Airfoil selection and wing design are core skills in aircraft preliminary design — this is day-one work for aero engineers
Drone & UAV Ops →
Fixed-wing drone designers must select airfoils optimized for their specific speed, payload, and endurance requirements
Pilot →
Understanding lift curves, stall behavior, and drag helps pilots make better decisions — especially in unusual attitudes
Aerospace Manufacturing →
Manufacturing engineers must understand the aerodynamic tolerances that drive surface finish and shape accuracy requirements
Go Further
Extend your aerodynamics knowledge:
- Build and test it — use balsa wood or foam to build the wing you designed and test it in a homemade wind tunnel or on a model aircraft
- Optimize for a mission — design a wing for a specific goal: maximum endurance, minimum stall speed, or fastest cruise
- Try OpenFOAM — move to CFD simulation and compare the XFLR5 results with full Navier-Stokes solutions
- Enter AIAA Design/Build/Fly — university teams use XFLR5 extensively in this premier aircraft design competition