Airbrake
Spaceport America Cup 10k OTS 2024 - UVA Rocketry - Sabre 1
Purpose
In order to get as close to the 10,000 ft goal-apogee outlined in the Spaceport America Cup 10k guidelines, it was determined that, if effectively designed and implemented, an airbrake system would be necessary. It was a no-brainer.
Design
Why does it look like that?
There are a lot of ways to create drag on a projectile, but we narrowed our design down to two models: four flaps which raise off of the body, and three petals which extend out of the body. While a four flap design is prevalent among modern aircraft and has been used on rockets for this exact competition, we decided that the system would be too complex for the team’s first attempt at an airbrake, as reliability and learning were our primary objectives. So, the three-petal system was selected.
How did we model it?
SolidWorks was used to model the airbrake system, mostly because there is now a course dedicated to the program and it’s extensive simulation capabilities. Once the parts that were required to make the system function were determined and a rough mockup was complete, parts were assigned to each member of the subteam to CAD.
Until Next Year…
Using FEA and CFD in SolidWorks, it was determined prior to our first subscale launch that the airbrake would not be suitable for launch day, unfortunately. The break in the body significantly impacts the structural integrity of the rocket, and remaining steadfast in ensuring reliability and simplicity, it posed too great of a threat to the success of the launch in New Mexico. However, attempting to implement an airbrake was not at all a waste of time—it taught us a lot about the importance of a structurally sound body, the design and feasibility of fielding a relatively complex system that experiences a load, and our capabilities as a team to do so. And it’s pretty cool.