The UW FSAE team is divided into eight technical groups broken up into the major systems of a race car. They are led by a student that is either a 2nd year member of the team or is experienced in the particular discipline.
The black magic of racecar engineering; turning air into grip. With new, more restrictive aero rules the aerodynamic design of the car must become more efficient to produce the maximum level of downforce in order to get the car around the track as fast as possible. By producing negative lift (downforce) we increase the normal force acting on the tires, letting the car corner faster without losing traction. Even small improvements in lateral acceleration can have a huge impact on our success at competition. Thus, a strong aerodynamics package is an essential part of our current vehicle design.
As a team, Aerodynamics touches many disciplines, from vehicle dynamics to fluid mechanics to composite structures. They are responsible for complex parts that must be both light and aerodynamic, yet also able to withstand significant loads. Student designers use industry grade computational fluid dynamics, finite element analysis, full-scale wind tunnel testing, and on-track evaluation to develop and validate a lightweight high-downforce package.
Chassis team designs and manufactures the carbon fiber composite monocoque chassis, the most architecturally critical component of the car. As the main structural component of the car, chassis team works with all other technical teams in order to seamlessly integrate each system into a completed racecar. Not only responsible for the chassis itself, members on chassis team must design safety devices such as crash structures for impact attenuation, as well as all driver interfaces to maximize in-car comfort. Over the course of the summer, the chassis goes through extensive design iterations, combining structural analysis, driver ergonomics, vehicle packaging, and functionality, to be ready to manufacture the following year. Additionally, care must be taken to comply with competition rules, all while achieving stiffness goals, chassis weight, and ease of maintenance with minimal compromise. All of these design aspects are carefully optimized to allow the car and driver to become one in order to compete at the limit of human performance.
The drivetrain system is responsible for the transfer of power from the engine/motor to the wheels. High strength aluminum and steel alloys are used to keep the system as light as possible. This results in many high tolerance CNC-machined parts that are designed and built by students. The drivetrain system also serves as the mounting device for the engine/motor.
For the combustion car a Drexler differential is used at the heart of the system. A chain drive system delivers the torque from the engine to the differential, and out to the wheels through a CV-Halfshaft system. As for the electric car, two inline planetary gearboxes are the heart of the system delivering torque to the wheels independently through the CV-Halfshaft system
The electronics team carries out all electrical projects other than eTrain projects for both the combustion and electric cars.
- Wiring: Wiring includes designing the wiring, as well as installing the actual wiring for both combustion and electric cars. This project gives a good overview of the whole system. It is crucial to have good documentation for this project.
- Driver Interface electronics: Driver interface electronics are what we use for driver-car communication. Projects include dash electronics, steering wheel electronics, and a mini heads up display.
- Data telemetry: Our data acquisition system uses the EngineLab ECU to monitor and log many aspects of the car. This data is valuable for engine tuning and providing driver feedback. It also help us improve our load cases, helping us build a lighter and stronger car. This year we are also expanding the system to provide real-time telemetry, allowing race team to watch critical data while the car is driving.
- Sensors: There are hundreds of sensors in the cars. For instance, strain gauges sensors, wirelesss torque sensors for half shafts, yaw rate sensors, temperature sensors, wheel speed sensors, etc. This project involves sensor selection, installation and data acquisition.
- Control Modules: One of the control modules is the fuel pump PWM module for the combustion car. There will be more projects as the year goes on.
The eTrain team is responsible for the systems that safely store and deliver electrical power from the batteries to the drivetrain. This is realized through four general subsystems: the batteries, the motor, motor controller, the safety systems, and the main controller. For this first year we are going with a single motor and differential design with a lithium polymer based battery pack for simplicity and cost. The crucial need to minimize the weight of the system has driven the majority of our design decisions on the car from the motor and controller to the batteries. The motor we are using is an Emrax AC motor that can output 80 kW (~110 hp) peak and yet only weighs 12 kg (~26 lbs), yielding one the highest power to weight ratios available for this size of motor. To power the motor, we have designed an accumulator pack that can store 5.8 kWh of electrical energy, which means that it could output 5.8 kW (7.8 hp) for an hour. For reference, commercial electric vehicles store between 20 to 40 kWh. The car is also outfitted with extensive safety systems that make it reliable and safe to operate.
Manufacturing Team is a supplementary tech team intended to aid the other tech teams with their metalworking and machining tasks while giving newer and less experienced members a solid foundation in manufacturing processes. Understanding how parts are manufactured is imperative for designing parts that are both effective and practical. Manufacturing Team members are often tasked with helping other members produce parts or with projects that are necessary for the team to function, but are not directly attached to the car. These include things such as testing rigs, quickjacks, or the pit cart. The experience gained while on the Manufacturing Team is something that can't be learned in a classroom and gives our newer members the confidence to take on difficult design projects in the future.
The suspension team is in charge of components such as the a-arms, uprights, wheels, tires, shocks, brakes, and steering geometry. This particular area of the car is very important since most auto-x racing is highly dependent upon the suspension setup. Design begins on the computer using suspension geometry software. Various iterations are tried until a perfect setup is found. Each UW Formula Motorsports car has utilized a short-long arm 4-wheel independent suspension with front and rear pullrods.