BEYOND SURFACES

converted from direct to alternat- ing. This generates heat that must be dissipated.” For the 2017 season, the KA-race.ing team decided to use their own tailor-made power electronics to save weight. The cooling plate was one of many components that they designed themselves. Felix Sanke says: “The helix structure increases the surface area, similar to a radiator, and in addition, a spiral flow is induced in the water. This means that many more water particles are ‘whirled about’ and come into contact with the boundary layer, thereby transferring heat to it. At first, we wanted to mill the part, but that proved to be unfeasible technically. That’s how we arrived at additive manufacturing, where you have almost total freedom in design.” With success, as it turned out: The cooling plate helped to reduce the total weight of the power electronics from 10 to 4.3 kg, which is not insignifi- cant given the total vehicle weight of 180 kg, and its performance was also more efficient. Peter Böttner, Business Developer at Oerlikon AM in Barleben, was impressed by the young engineers’ professionalism: “Not only did they have a clear idea about what the cooling plate should look like, they also knew what possibilities additive manu- facturing offers. Together, we considered what was technically feasible, and then the team gave us the final CAD data completely ready to print the cooling plate.” The KA-race.ing team was very successful with the new car in the 2017 season, when it took second place three times. The following year, the plate originally developed by Felix Sanke was optimized once again by his colleague Robin Schillinger, who further improved the cooling per- formance and reduced the weight by another 14%. “We deliberately went to the limit to find out what is technically possible — but it still held up,” says Felix Sanke, pleased that the delicate design performed perfectly not only in the 2017 and 2018 seasons, but also in 2019. KA-race.ing, KIT and the Formula Student Formula Student is an international design competition for students. Around 900 teams compete against each other in self-built race cars — internal combustion, electric and self-driving. Formula Student Germany at the Hockenheim-Ring is one of the most important of these races, with about 3,000 students from all over the world. These next-generation engineers are concerned not only with speed, but also with the teams’ and cars’ overall performance. “KA-race.ing, the racing team of the Karlsruhe Institute of Technology (KIT), is the only team that has always been represented in all three disciplines,” says Felix Sanke, who was Technical Director in 2018, supported the 2019 team in an advisory capacity, and is currently completing his master’s degree at KIT. The plan called for participation in Formula Student in 2020 with one autonomous and one electric vehicle — until the racing season was canceled due to the Covid-19 pandemic. www.ka-raceing.de Beyond SURFACeS 02|2020 13

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