Design 2.0

Featured, General, Structures / Monday, December 9th, 2019

We are finally wrapping up the design phase and transitioning into building our second solar car. We plan to remain faithful to the first design’s successes while making significant changes to the exterior layout and solar array. 

The most fundamental change is to the body of the car: In order to reduce drag, we’ve moved the solar panels from a canopy above the driver to a flat plate at shoulder height integrated into the chassis. 

This year’s race will be formatted in the same way as the 2019 challenge at the Texas Motor Speedway where the winner will be determined through an endurance race over 4 days of competition.

Junior Joseph Nwizugbo and freshman Hailin Truman testing the “mockpit”.

Here is a quick guide to winning the race:

  1. Don’t break down.
  2. Maintain the highest average speed.

These two steps guided our design priorities – reliability and efficiency.

The first priority is reliability:

When we have the option between simple and complex, we always lean towards simplicity . I’ll be frank and describe the experience driving the car as thrilling and rewarding, but smooth or relaxing are two adjectives that I would not use. The whole car vibrates like a washing machine while driving, and the rush of air will leave your skin with goosebumps.

It’s clear that the constant vibration doesn’t play well with fragile parts, so when designing, we have to remind ourselves that every joint, diode, and bolt will be expected to last for a few hundred miles.

The second priority is efficiency:

Due to the event’s long duration, even small inefficiencies will compound into a larger issue. The largest factor that slows us is drag. In fact, the drag force is proportional to the square of the car’s speed, so as we drive faster, the energy depleted from the battery will sharply increase. Any decreases in drag will make significant improvement in performance.

Belgium Agoria’s solar car traveling through Australia during the 2019 World Solar Challenge.

This is why we have decided to bring the solar panels to shoulder height. Above is the champion car from the 2019 World Solar Challenge. It features a sleek design with the two pods resembling a catamaran. This champion car is similar to the design we intend to achieve. 

Our proposed design will decrease our frontal area, a major source of drag, and enable greater efficiencies, especially at higher speeds. This goal does not come without its drawbacks. The cockpit section will use up key space for solar panels. Based on our calculations, we’ll lose access to 400W of solar power, bringing our total down to 1,400W from 1,800W.

A full body model of our design rendered in Autodesk Inventor.

Thanks to our sponsors, we have been planning a design that uses a variety of materials. Like last year, we will construct the chassis from steel due to its strength and ease of construction. Students of all ages are learning to weld in preparation for the construction.

Our design also incorporates composites for its light but rigid properties. Boeing and their partner, The Gill Corporation have donated honeycomb panels that we will incorporate into our solar panel support structure.

Our team has already constructed a chair from these panels, bonding them together with fiberglass and epoxy.

Team members are enthusiastic about bringing the design to life, building and testing their hard work after the new year.

We are very excited to evolve our design and glad to have your support!

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