Baja SAE
Baja SAE works on the design, fabrication, and racing of custom off-road vehicles in collegiate competitions each year. As a part of Baja, I was able to get involved with the machining of several components on the car.
I was also involved in the drivetrain subteam where I worked to solve the problem of overheating in the CVT case with a custom impeller and worked on a gearbox sizing script to find the optimal sizes given a desired ratio.
Impeller Design and Simulation
Problem: During competition in California, the continuously variable transmission (CVT) case was overheating and causing the belt to glass over. The current case has no outlet and insufficient airflow going through it with the existing impeller. Below are the CVT case and existing impeller and the new impeller I designed.
Solution: I ran simulations in COMSOL to determine the optimal outlet port position and designed a new impeller that would provide higher airflow in the case. I started with recreating centrifugal pump models from COMSOL's examples to get a handle on fluid modeling.
After getting used to fluid modeling, I modeled our current case and tried different outlet positions to see where would be the best. I then did research into different impeller types, their purpose, and what metrics are measured in simulations. I ended up going with a backswept impeller which would help pull air into the case. I optimized the design for size and number of blades, using pressure head against mas flow as a metric, and 3D printed it to try on the car.
Gearbox MATLAB Script
Problem: Once a gear ratio is chosen, the gear sizes (2 stage reduction) are chosen and iterated by hand in an excel spreadsheet. This is extremely time consuming and doesn't allow for quick turnaround if multiple ratio sizes are needed.
Solution: I wrote a script in MATLAB that would take in inputs for total desired gear reduction, center to center distance required between each pinion/gear combo, density, gear dimensions, FOS, and would output viable gear combinations. The script would check each gear set for interference, contact stress, bending stress, static stress, weight, and moment of inertia. It would then output viable solutions under a set mass and inertia. The script would check through all standard and non-standard teeth sizes as well as varying face widths for the gears. The condensed list could then be checked through and picked from based on manufacturing cost and any other preferences. Below are inputs for the script and an example output of a viable ratio
