When you look at a racecar, the first thing you see is, naturally, what’s visible on the outside of the car. You see the body of the car, the tyres, the wings, the steering wheel and so much more. Our Mechanical department is responsible for these aspects of the car, and today we are delving deeper into what this department is all about.
The Mechanical department works to create the most optimized structure that can keep the racecar in contact with the tarmac at every part of the track. In racing, it all starts with the tyres, then we move on up the suspension, into the dampers and finally have the forces absorbed by the chassis. Every system is part of a larger chain where we try to understand each of the forces acting on the parts.
Four groups make up this department: Aerodynamics, Chassis, Suspension & Drivetrain and Driver Interface. They work as individual groups to make their respective systems and have individual goals, but these goals are based around the team’s overall goals. This makes us able to create systems that work well together and makes for a high performance racecar. Let's talk more about each group.
The race tracks we drive on are rather small and have more turns than straights. This makes it challenging to drive fast. One of the ways we are able to crank up our speed is by utilizing aerodynamic wings. Making an excelling wing package is the responsibility of the Aerodynamics group. They also influence the designs of other groups such that they benefit aerodynamic performance. The main target of the group is to increase the total downforce acting vertically towards the ground, and to minimize the drag acting in the opposite direction of the heading to allow for higher cornering velocity.
This is done through an iterative process that consists of designing concepts with Computer Aided Design (CAD) and testing the designs in simulations. The group uses Computational Fluid Dynamics (CFD) software from Siemens STAR-CCM+ combined with a supercomputer to run these simulations.
The group also works to optimize the accuracy of the production of the different elements as well as doing research and validation work to ensure that the aerodynamic devices and the car as a whole resemble what has been designed and simulated.
The biggest part of the car is the monocoque, and that’s the work of the Chassis group. Since this is the car’s main structure, all the other systems are connected to this part. To support everything, including the driver, the chassis has to be strong, but it should still be light. Therefore, materials like carbon fiber and aluminum honeycomb are used. Through extensive analyzing and testing, the carbon fiber lay-up is optimized for both strength and low weight. What’s even more important is the safety of the driver. For this reason, the Chassis group is also responsible for making sure their system is safe for the driver.
To actually build the monocoque, the group travels to Kongsberg in February to use Kongsberg Gruppen’s facilities. Here, the group gains valuable knowledge of the advanced production method using carbon fiber.
The Suspension & Drivetrain group is responsible for every part connecting the car to the road. The group works with the suspension, upright, gearbox and motor, all packed tightly inside each wheel. The suspension aims to have the optimal balance between keeping the tyres in right contact with the ground, and holding the vehicle as stable as possible. It has to be lightweight while still withstanding the forces acting on the car in steep turns.
The drivetrain consists of an electric motor packed inside each wheel, capable of delivering 80 kW in total. The motor connects to a planetary gearbox designed specifically to deliver the best performance possible.
Designing the suspension and drivetrain is no easy task. The systems contain more parts than any other system on the car, with over 1 700 parts!
The design begins in CAD, and then is analyzed in FEM to verify its strength. Most of our parts are machined in aluminum and titanium. However, we also use carbon fiber in the suspension rods and the rims.
When Suspension & Drivetrain does an extra simulation on strength and buckling, the Driver Interface group checks for comfort and how systems interact with the driver. This group is responsible for the brake system, pedalbox, steering system and ergonomics. It is closely related to Suspension & Drivetrain but has a larger focus on the human-car interaction of the car.
They use both alloys and composite material in their design. This results in a group that has a good understanding of production methods relevant for both fields. The most utilized tools are the classical free body diagram, accompanied with Abaqus for simulations. To CAD the group uses, like the rest of Revolve NTNU, Solidworks. When the design is done and sent to production, Driver Interface is the second group after Chassis to assemble and mount their systems on the car.
This year, we are aiming to have a test ready car by the 1st of May and are excited to see the car make its way to its final form in the workshop.