Testing & Diagnosis

Behavioral airflow

  • challenge

    • Observed a large discrepancy between the simulated and measured drag coefficients, indicating unexpected aerodynamic behavior

    • Needed to understand how air flowed over and around the vehicle under real conditions to identify sources of drag

    • Required a practical testing method to pinpoint aerodynamic inefficiencies and areas for design improvement

  • approach

    • Instrumented the solar car’s aeroshell with tufts (light strings) to visualize airflow direction and behavior during testing

    • Conducted behavioral airflow tests on a closed road highway to capture high-speed photographs and video evidence of airflow movement

    • Analyzed tuft motion to identify regions of separation, turbulence, and reversed flow across the shell

  • solution

    • Discovered a “parachute effect” at the leading edge, where tufts were pulled inward, indicating unwanted air ingress

    • Identified a continuous gap between the upper and lower shells, contributing to drag and turbulent separation

    • Determined that the rough aeroshell surface and localized turbulent zones further degraded aerodynamic performance

    • Used test results to pinpoint areas for refinement in sealing, surface finish, and shell geometry to reduce overall drag and improve aerodynamic efficiency

Dynamic testing

  • challenge

    • Demonstrate compliance with American Solar Challenge performance rules for Figure-8, Slalom, and wet-surface braking

    • Develop a test plan for a closed-road facility while ensuring driver and bystander safety

    • Achieve specified performance targets (≤ 8.0 s/side Figure-8, ≤ 11.5 s Slalom, ≥ 4.72 m/s² wet braking) to pass scrutineering for the Formula Sun Grand Prix competition

  • approach

    • Developed a formal closed-road test plan specifying facility layout, safety briefings, observers, and safety mitigations

    • Executed course setups per ASC geometry (Figure-8 cones, 18 m slalom spacing) and prepared the braking zone with controlled wetting for repeatable wet-stop runs

    • Varied tire pressure to establish to establish performance/efficiency tradeoffs

  • solution

    • Collected, documented, and analyzed telemetry and video for all runs

    • Figure-8 and Slalom runs consistently met time targets with clear margins (all runs ≤ required times)

    • Wet braking tests produced average deceleration above the ASC minimum (average ≥ 4.72 m/s²), confirming stopping performance on a wetted surface

Tracker vehicle optimization

  • challenge

    • Use an autonomous line-following car that could not reliably stay on track and change the poor turning logic

    • Gain a faster response from the vehicle that could stay on the course and complete the loop faster than the other groups

    • Alter sensitivity and control code to achieve consistent, precise, and fast behavior

  • approach

    • Redesigned the control logic to optimize wheel speed balance and improve turning dynamics to stay on the line

    • Implemented logic for lap counting and automatic stopping after the three laps

    • Iteratively tested and tuned system parameters to find an optimal sensitivity and response level.

  • solution

    • Developed a higher speed and more stable control algorithm that eliminated erratic reversing and improved turn precision

    • Achieved consistent track-following performance and automated lap tracking logic

    • Placed in the top 3 for fastest vehicles around the loop