Motorsport has always been the test bench that allows the most innovative technologies to arrive on our road cars
In recent years, the increased awareness of pollution-related problems has pushed many car manufacturers towards the evolution of engines which, in the wake of Formula1 and FormulaE, will focus on hybrid and electric technologies.
In this scenario, Formula SAE, a competition that allows engineering students from all over the world to taste the world of racing, also plays the role of a springboard for new developments in the automotive world. The spirit of this world “championship” (in addition to the substance of its regulation – ed) is precisely to encourage the development of new solutions that combine performance with the right balance between costs and benefits.
Il Team Dynamis PRC del Politecnico di Milano, which since 2004 has been taking part in the various stages around Europe, has reached the 4th place in the world ranking for the Combustion category in 2019 after a year full of successes and is preparing to start the 2021 season (alas 2020 did not see races) with a completely new car, electric and 4WD.
This is a radical difference as the different masses, their distribution, the management of the batteries, the temperatures and the 4 driving-wheels are just some of the trials that the engineers will have to deal with during the season.
Taming the potential of 3D printing thanks to DfAM and fully exploiting it to find innovative solutions is an exciting challenge for us at PUNTOZERO too: the possibility of experimenting on the field a mix of technologies, simulation software, “alien” geometries and new materials conception was too inviting to back down.
Cooler, Lighter, Faster, Better.
Among the various car systems that we analyzed with the guys from Team Dynamis, the heat exchanger that cools the inverter unit seemed to us an excellent candidate to push the limits of design thanks to additive technologies.
The objectives of the project? Mass reduction and improvement of heat exchange, without however penalizing the power absorbed by the water pump and the mechanical strength of the assembly.
The starting point is an exchanger made using traditional machining technologies and optimized at a fluid dynamics level to minimize stagnation areas and thus improve heat exchange with the heat-plates of the inverters.
Thanks to an appropriate design, which sees 3D printing as a production technology, we have been able to take all this to an even higher level.
1) The use of gyroidal structures for the internal channels has allowed us to increase the exchange surfaces by 300%;
2) By modulating the geometry through computational design and using the results of CFD simulations as input to redistribute the density, we were also able to minimize the increase in pressure drops, keeping them in the optimal operating range of the water pump;
3) We have also implemented lattice structures for the external structure to reduce the weight of the component by about 20% (essential in the racing world), while maintaining the strength of the assembly.
Tools
In the world of additive manufacturing, technologies and materials are constantly (and rapidly) evolving. If knowledge and methodologies do not keep up, evolution is not much use. For us designers, and in general in an increasingly digitalized world, modeling and analysis software are one of the most important tools.
In this context, nTopology fits perfectly with our approach. In addition to being a software that supports design in a completely different way from classic CAD, it allows solid components, surfaces, FEM analysis, CFD analysis, etc. to speak the “same language”. There is no translation, everything is number. The advantage? nTopology
has one of the greatest strengths in its structure, which leads you to work step by step and each step has its own function not its own memory. This allows us to validate workflows and even experiment others, to get a repeatable and, above all, reusable modeling process.
PURE aluminum.
m4p, an important reality in the production of alloys and powders for 3D printing, has put the icing on the cake with their innovative m4p™ PureAl material: an almost pure aluminum alloy that boasts high electrical and thermal conductivity values (a key feature for this project), but with fewer problems related to rapid oxidation with respect to the other materials evaluated as possible alternatives for this application.
The enthusiastic support and the desire to get involved were decisive for the development of the project. They made available EOS machinery, reliable and precise, and a new alloy whose technical and technological limits they wanted to test (and the geometry is really crazy – ed): the skill and experience of technicians and engineers was then fundamental to optimize the printing parameters and achieve the goal
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The track doesn't lie.
Additive technology has also allowed us to bring developments quickly and in these days a further iteration of component evolution is underway: this should guarantee improved performance and an even lower weight.
In the coming weeks the team will go to the track to test the new car and all its components to be ready for the summer races: it will be there that we will have the confirmation on the reliability and performance of the exchanger, and we are confident that it will contribute to a competitive season full of satisfactions for the Dynamis Team.
In collaboration with
PUNTOZERO
Design for Additive Manufacturing
Contact
- info@puntozero3d.com