BASIS Aerodragons Rocketry Team
ROCKETRY
This is our first year as a rocketry team, and we have been working all year designing and constructing our rocket. We are participating in the Team America Rocketry Challenge (TARC) and are currently working on a revolutionary design to get a perfect score on every flight. We've participated in many events to increase our knowledge and branch out to the wider STEM community. Here are some notable experiences and aspects of our team from this year.
Our Team
We are team 177 BASIS Aerodragons and have 10 members on our team. Our team values are innovation and inspiration. We are constantly trying to bring unique ideas to the TARC competition as well as inspire others to do the same.
The Challenge
The annual Team America Rocketry Challenge (TARC) is the worlds largest student rocketry competition in which thousands of student teams compete to launch their rocket closest to the specified altitude and flight time.
Our Design
Design Overview (An OpenRocket Design)
The airspeed sensor is mounted at the top for real-time airspeed to be used by the flight computer which is located right below the nose cone along with the Pnut altimeter. The nose cone was modified at the top to make room for the airspeed sensor and also modified at the bottom where a compartment was made to hold the egg. This compartment consisted of foam padding in the top of the nose cone and fluffing in the bag of the egg to prevent it from breaking in the compartment. The fins were canted slightly forward to ensure structural rigidity on the off-case of a parachute failure. The parachute deployment was chosen to be at the bottom of the body because the air brakes would prevent the pressure from the ejection charge from reaching the nose cone. Here, 2 parachutes of area equaling 0.246m2 reside to reduce the chance of a parachute not deploying. Finally, we had adjustable mass at the nose cone to achieve the desired fin effectiveness and predicted altitude. Fin/motor/body dimensions were iteratively designed.
Adaptive Airbrake Mechanism (AIM)
Our Adaptive Airbrake Mechanism (AIM) allows use to achieve the desired altitude every flight as it can change mid-flight depending upon our rocket engine, weather, and trajectory variability. It uses a 24-bit high precision pressure sensor, pitot tube airspeed sensor, and gyroscopic technology to effectively know when and how long our airbrake mechanism remains open to achieve the perfect altitude. Additionally, our dual-stacked CAM mechanical airbrake design allows for improved altitude control via precision airbrake impulse timing.
Computational Fluid Dynamics (CFD)
We use SimScale, a cloud-based CFD platform, to accurately determine aerodynamics forces and coefficients on our rocket design to optimize our flight controllers accuracy. Our CFD simulation's also allows for use to iterate our rocket design to reduce drag.
Accurate coefficient of drag shows with convergence in simulation
Y+ values indicate the accuracy of ouur CFD steady state analysis
Pressure analysis of different sections of the design
Particle trace visualization of airflow around the rocket
Flight Controller Program
Our flight controller uses a custom program to know exactly when and for how long it needs to open the airbrakes to achieve the desired altitude. It does this by repeatedly checking if the overshoot altitude is greater than zero and if so the airbrakes stay open. The calculations are calculus-based aerodynamic equations that we derived to account for drag and its coefficients found with our CFD simulation.
Materials Engineering
Since our club doesn't receive monetary aid from the school, we use innovative building techniques to ensure reusability, fast and inexpensive prototyping, and part quality. We used aerospace grade carbon fiber that was molded onto the rocket body with epoxy. This allows us to ensure durability while also keeping the rocket lightweight. For our fin design, we used balsa wood to keep them lightweight and allow them to be sanded down to an aerodynamic airfoil profile. We 3D printed our airbrakes to allow for rapid prototyping and testing and to allow us to have complete control over the object design. Finally, we modified our plastic nosecone to accommodate our airspeed sensor and egg payload.
Our carbon fiber fin design ensures maximal structural rigidly allowing us to reuse the rocket for many flights as it is more durable
Our 3D printed airbrakes and rocket tube connectors allow use to prototype faster and optimize our design by greater customizability
The Launch
The calculations performed in open rocket and CFD confirmation of CG/CP balance for the fin design worked perfectly: rocket launched completely straight.
The altitude of the rocket was an overshot as predicted in openrocket(283m:360m–real life: OpenRocket).
The staging portion designed to separate at the bottom of the rocket worked and stayed together.
The airbrakes malfunctioned in launch, despite ground testing perfection, and wouldn’t deploy. This was because the wire from the battery came detached from the arduino with the insertion of the egg.
Design portfolio - Click here if you wish to view our design process in detail and see all of our calculations. This is where the bulk of our work and testing is shown.