Purdue Aerial Robotics
I joined this team to further my knowledge of autonomous systems and their design methodology.
The goal of this team is to develop an autonomous flying craft that will participate in an Annual competition held by the Association for Unmanned Vehicle Systems International. I worked on the Airframe team primarily on system design and aerodynamics.
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To learn more about this team, you can visit their webpage: https://www.purdueaerial.com/
Contributions under this
Initial Sizing Code
Aircraft sizing codes for vehicles with electric-powered propulsion systems are not commonly found, or taught in classes. To effectively start the team’s design process, I developed a sizing code for electric aircraft using the equations of motion and battery energy density instead of fuel fractions. The sizing code used several parameters set by the team as input and produced the required Coefficient of Lift and Drag as output. You can customize it to add multiple segments of flight, for each flight the best Coefficient of Lift and Drag are produced.
Electric Aircraft Performance Graphs for Initial Sizing
Aerodynamic Plane Design
In order to save weight while maintaining good stall characteristics, our team decided to incorporate taper along with aerodynamic twist into our design. This required extensive testing and scouting for the ideal combination of airfoils and taper ratios. I led this effort and guided the younger members in using XFLR-5 and its analysis tools.
I also conducted dynamic and static stability tests on the aircraft. Since the team intended to use the tail from the previous year, I had to work around the 2 phugoid modes caused by our design. The solution I came up with moved the center of mass of the aircraft slightly behind its nominal point. To compensate, I then increased the angle at which the horizontal tail attached to the fuselage. Through trial and error of these two principles, I arrived at a solution that almost made the system stable. We chose to leave it unstable in order to aid maneuverability.
Wind Tunnel Testing
To get the right performance out of our tapered and twisted wings, we had to choose slightly unconventional airfoils. In order to validate the airfoil's performance, I decided to use the wind tunnel on campus to test a 3-D printed model of our airfoil. We tested the tapered and twisted wing, along with a plane airfoil wing to validate XFLR-5’s prediction. Our data indicated that the 3-D printed airfoils stalled later than the XFLR-5 prediction, and produced more drag. We attributed this to the 3-D print lines on the airfoils acting as vortex generators. I used Siemens NX to CAD the wing sections.
I oversaw this project from start to finish, and was responsible for managing logistics, and system integration to ensure our test was compatible with the wind tunnel.
