Projects

SP80 becoming a case study for EPFL lessons

June 1st, 2020

The team’s enthusiasm for chasing and breaking the world’s speed record has started to spread among EPFL’s student community as well. SP80’s strong willed and determined spirit has inspired three Masters students in Mechanical Engineering to illustrate their lesson on Particle-based Methods within our project. We had the opportunity to discuss with one of them, Alexis Couturier, to further understand their work and motivation.

Particle-based methods: a new way of dealing with fluid simulations! 

The complexity of analysing movements of fluids such as gas, oil or water can be counteracted thanks to several tried and tested scientific methods. The most recent one, the particle-based approach, helps understand large fluid displacements by modelling a fluid as billions of small particles. “Consider it simply as throwing an object into a ball pit and analyzing where the balls are moving!”, explains Alexis Couturier. This kind of reasoning makes the Particle Based method a powerful tool to understand how the fluid is evolving within its environment. This approach has been used beyond engineering applications. For example, Narnia’s film The voyage of the dawn treader used this method to realistically model the waves and water displacements.

From theory to application

“At first, the professor suggested we study the simulation of snow flows generated by an avalanche. However, as a former member of the EPFL Racing Team, I proposed we study the oil displacement within the gearbox of the team’s car. After talking with Benoit Gaudiot (ie. one of SP80’s co-founder), I proposed to my teammates to work on SP80. It is quite challenging to study boat displacements at such high speeds!” tells Alexis. He quickly managed to convince Adrien Roux and Adrien Peltier, his two co-workers. “We decided to study two precise cases of SP80’s boat behavior: the acceleration phase and the deceleration phase. To do so, we simulated the boat going from 108 km/h to 144 km/h and then the other way round. The surrounding water was modeled using 10 million particles, meaning more than 20 hours of simulation for each case!”. Since the particle-based approach is still in development, Alexis had to do several iterations to find the most accurate parameters, a lengthy task which is definitely worth it – the results are stunning! 

Furthermore, the initial simulation images have gone through post-production to get the final results. Adrien Peltier made sure the resulting images were beautiful, realistic and scientifically accurate. By using the Particle Based approach and the post-production software in conjunction, Adrien created a highly realistic and detailed model. This is how he modeled details such as the scum on top on the waves.

An added value for the global SP80 project 

Throughout their work, the three students were in close link with  the SP80 team and more precisely with Charles de Sarnez, our fluid team manager. Charles commented that “having students discover this new method of fluid analysis and apply it to SP80 is a perfect opportunity for us to further understand the behavior of the boat at high speed. With particle-based methods, we can visualize the shape of the water spray formed behind the boat at record speeds and this cannot be done in other ways.” All the work achieved by the three students is a great addition to what is currently being done with Orca 3D and Simerics software. As we better understand the boat’s physics and behaviour, we get closer and closer to breaking the speed record.

Thanks again to Alexis Couturier, Adrien Peltier and Adrien Roux for their contribution to SP80.

Aurore Kerr, Community Manager
David Sanchez, member of the performance prediction team