Last week the FSAE Electric Racecar team was able to finish the design of all of the printed circuit boards in the low voltage system. This includes a number of vital components, including several control circuits and safety devices. Completing these designs is a major step in developing the racecar as designing these systems was a major obstacle for the 2016-2017 FSAE Electric Racecar team.

This week, Khue Pham will be describing the process of designing the body.

The process of designing the FSAE Electric Racecar's body consisted of designing the body in Solidworks, analyzing aerodynamics results utilizing Solidworks Flow Simulation, and making iterations based on the analysis. The main goals of the body are to increase downforce and minimize the aerodynamic drag for the vehicle, as well as creating a lightweight and aesthetically attractive design.

Starting with the design process for the nose, Solidworks loft and surface features were used to create the smooth curves around the front bulk head of the chassis. The FSAE rules require the nose must not have forward facing radius smaller than 1.5 inches and must extend at least 45 degrees relative to the forward direction. Side panels were designed to streamline the sides of the chassis up to the battery box with minimal sharp curves to reduce the drag.

Due to the complicated geometry of the chassis, suspension, batteries, and powertrain, a simplified version of the chassis is used for the simulation in order for Solidworks to run. After running the body design through Solidworks Flow Simulation with the 45 mph moving ground, 100 degree Fahrenheit temperature, and normal forces in Y and Z directions; Solidworks calculated a lift and drag of 8 lbf and 26 lbf, respectively. Iterations were then made by fixing the curvatures dimensions and geometry, the lift was reduced to 1.8 lbf with a cost of increasing in drag to 29 lbf.

A trade study was done to determine what material to construct the body before the actual manufacturing process. Carbon Fiber, despite its high strength-to-weight ratio and low weight, was not chosen because its conductivity makes it risky to use on an electric car (FSAE rules require all components that may become conductive to have a resistance to ground below 5 Ohms). Fiberglass was determined to be the best option for nose and undertray due to its non-conductivity. While birch wood was determined to be the best material for the side panels, also due to its low conductivity.