The 2012-2013 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 race car engineering; turning air into grip. With new rules and a single cylinder engine, the aerodynamics of the car must become more efficient to produce the optimal level of down force to get the car around the track as fast as possible. Producing up to 50% of the car's grip at 35mph, and contributing less than 5% of the car's weight, the aerodynamics are crucial to the success of the car. Student designers use industry grade computational fluid dynamics to simulate the car. Additionally, students will put the car into a full scale wind tunnel to correlate computational to real world testing. Finally the car will be full scale tested on a autocross style course.
The chassis group deals with the structural components, safety devices, outer bodywork, and driver interfaces on the vehicle. Responsible for the most architecturally critical component of the car, chassis group commands the most aggressive timeline of the technical groups. Over the course of the summer, extensive development work goes into designing the chassis which will compete in June and August. Throughout the development cycle, consideration of safety rules, vehicle packaging, stiffness goals, chassis weight, and ease of maintenance are all balanced using advanced computer analysis software and testing to achieve the best overall design. Changes to the outer bodywork will ensure desirable air flows over the vehicle, significantly improving high speed operation. Further optimization in the driver interface systems (including the seat, display, shifter, and pedals) will allow the most important part of the car, the driver, to effortlessly compete at the limit of human performance.
The primary goal of the Driver Controls is to improve drivability of the car. Comfortable drivers who can easily control and interact with the car will drive faster. This team focuses on removing distractions within the car so that the drivers can focus on driving. The secondary goal is to make parts as light as possible while still fulfilling their functions. Even small weight savings here and there will add up to large weight savings across the car.
The drivetrain system is responsible for the transfer of power from the engine to the wheels. A Drexler differential is used at the heart of the system. A chain drive system delivers the torque from the engine to the differential. 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.
Engine and Electrical
The engine team is responsible for delivering consistent, drive-able power to the car, while maximizing performance and reliability. Projects include design and construction of intake, exhaust, throttle and fuel system as well as concurrent development of engine management system, data acquisition and engine tuning. The team uses Ricardo Wave models and acceleration simulations for simulation and evaluation criteria. Refinements to existing equipment make engine tuning and testing even easier, along with improved tuning goals and methods which optimize fuel consumption, power, and reliability. The Yamaha WR450 engine we use in our car already has outstanding power output, around 100hp per liter, which is right up there with the most advanced naturally aspirated engines in the world. Our goal this year was to not only increase the power to displacement ratio, but also increase the overall displacement of the engine, hopefully producing upwards of 55hp. To accomplish this goal, we will be doing a number of extensive internal modifications and then tuning the fuel and ignition systems to produce maximum power, because what’s a race car without an awesome engine?
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 in charge of showing new members how things are made in efforts to learn what the classroom cannot team. By understanding the limitations and freedoms of manufacturing, members are able to incorporate this knowledge into their design. Manufacturing team also helps develop testing rigs and methods for spring quarter. These capable members also help other members with design projects with their specific manufacturing knowledge and abilities.
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.