Formula Race is an international competition that challenges teams of university students to conceive, design, fabricate, develop and compete in a race car. For the contest, four categories of vehicle types are accepted. The Formula Student Team Delft participated in the Electric Vehicles (EV) category in 2018 (Fig. 1).
In an EV, the electric motor is responsible for converting electrical into mechanical energy (Fig. 2). When in operation, some electric motor components generate heat, such as the rotor and stator losses. In order to prevent a heat-induced breakdown, the motor must have an appropriate cooling system.
For many reasons, an efficient cooling system should control an electric motor's operating temperature. The first one is to preserve the insulation of the winding wire, which is one of the components most susceptible to overheating. The insulation lifespan is shortened if performed at higher temperatures, causing premature failure.
Another reason is motor efficiency. The winding resistance is increased with high temperatures, reducing the motor efficiency. Additionally, when the motor overheats, the permeability of the magnetic steel in the engine diminishes, lowering the amount of available torque. Lastly, bearing lubrication must be kept at lower temperatures because it might result in early bearing failure.
As the cooling system has a crucial impact on the lifetime and efficiency of the motor, an adequate design changes the entire vehicle's performance. Therefore, Formula Student Team Delft collaborated with Diabatix to have a cooling jacket for their racing car.
Our cloud-based platform, ColdStream, developed the 3D printed motor cooling jacket shown in Fig. 3, using the Generative Design package.
The mounted cooling jacket in the Formula Student Team Delft car is shown in Fig. 4.
The results of the generative design jacket were validated with a conventional spiral cooling design. Diabatix's design reduced the required battery power for cooling by 80%, significantly improving the car's autonomy. The motor temperature decreased by 21%, promoting a longer lifespan compared to the traditional design. Additionally, both cooling jackets were tested simultaneously, mounted on each of the wheels with the electric motor. The temperatures were collected for two minutes after accelerating the racing car (Fig. 5). The results show that Diabatix's cooling jacket provides better thermal management than the conventional spiral cooling design.
Taking advantage of our cloud-based platform ColdStream, Formula Student Team Delft could generate a more efficient cooling jacket for their racing car. The custom design allowed them to reduce the temperature of the electric motor by 21%. Additionally, ColdStream autonomously generated the design, requiring hardly 10 minutes of engineering time to submit the case, allowing the students to concentrate on other parts of the racing project.
Formula Student Team Delft aims to design, build and drive an electric Formula Student race car. The group comprises motivated students from the renowned Delft University of Technology in the Netherlands. They are challenged to assemble their own vehicle in only eight months, which allows the team members to apply their technical and soft skills while creating a competitive machine.