Airfoil Design and Testing

Learning Objective

This project served to determine the coefficient of lift and drag of different airfoil shapes, such as a symmetrical shape. The effects of camber on lift and drag are to be determined using Inventor, Foilsim, and wind tunnel testing software.

• Students will design an airfoil using Foilsim simulation software.

• Students will create a 3d model of their airfoil from 1.2.6 that can be used to test the lift and drag characteristics of the airfoil.

• Students will test the lift and drag characteristics of the airfoil that they created and compare to the simulation results.

Project Description

The airfoil being tested had a symmetric shape. The airfoil was to be 4 inches wide, 5 inches long, and 2 inches tall. The airfoil was first simulated using FoilSim, and from there a model and sketch were created in CAD. The sketches were printed out, then spray glued onto aluminum sheets. The outlines of the airfoil, four in total (left front, right front, left back, right back), were cut out from the aluminum. Hammers and nails were used to create holes in the airfoil templates, which is where thumbtacks were used to secure the templates to a block of foam. From there, a hot wire foam cutter created the final 3D airfoil, by cutting along the template outlines. Approximately 1 class day was spent simulating the airfoil, 3 class days were spent constructing the airfoil, and 1 class day was spent doing wind tunnel tests.

What I Learned

I learned how to use the FoilSim software to simulate airfoils of different shapes at different velocities, altitudes, wing densities, and many other variables. This software allowed me to view the coefficients of lift and drag at different angles of attacks. I also learned how a wind tunnel works and how its components operate, along with how to use the software in order to view the lift at the optimal velocity.

Design Benefits

Since a symmetrical airfoil depends on the angle of attack for lift, these airfoils let the aircraft fly well both upward and downward, so these may be seen on aerobatic planes that are used for performing tricks. However, if a plane wants to get the most lift to speed, the most optimal shape would not be symmetrical. This shape does not utilize wind as much as other shapes to generate lift, which means it is more optimal to have a flatter bottom in order to have faster airspeed on the bottom. This would result in greater pressure on the bottom, generating lift.