Group Members
Steve Buell, Justin Harbert, Greg Allen, Tim Schlabach, Kurt Easton, Sara McWilliams, and Ben Shaw

Description
As part of class requirements, a group of senior students enrolled in Aerodynamics Lab created a Power Generation System for use with TSU’s Subsonic Wind tunnel. Working with TSU CAD majors they used the TSU rapid prototype system create a 3 propeller system. Each component was designed and created singly and then assembled for a final product. The blades were based off a Clark Y airfoil and were assembled into the spinner with the ability to adjust the pitch of each blade.

This propeller system was mounted to an alternator and attached to the wind tunnel’s mounting system as one unit. The alternator was used in the system to apply resistance to the propeller system therefore applying a load to the tunnel. The alternator was wired to a variable resistant load so that with changing wind speeds, resistance could be equally increased. Using this system and setup the system was able to measure the power generation of TSU’s Subsonic Wind Tunnel. The idea was based on measuring the RPM and torque of the system. With this information power could be calculated for the wind tunnel.

Many of the calculations for appropriate pitch angle and twist were optimized. Some problem areas of the design involve flexibility and stresses. Flexibility is an issue because the blades must be attached in such a way that they can be adjusted for different pitch angles. Stresses on the system are also an important design issue. The system was made using a rapid prototyping machine and ABS material that is printed in layers. Therefore, shear forces must be considered in the design steps.