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Eco-Runner Team Delft is a student team at the TU Delft.  Since 2005 our mission has been to design and build the most efficient vehicle powered by hydrogen.  There are two main aspects to this vehicle- a fuel efficient propulsion system and a vehicle with very little resistance.  The aerodynamic resistance is a big part of the latter.  Rescale’s cloud simulation platform allows us to design a vehicle with a minimal drag resistance.

Our team has been building fuel efficient cars for a decade.  This means that a lot of aerodynamic computations have already been done.  In order to further improve upon the previous vehicle, Ecorunner V, a comparison of different concepts was needed.  To gather reliable results for the different concepts takes a lot of time when limited to internal computation resources.  This is when Rescale entered the picture.

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Vorticity and pressure distribution over Ecorunner body

 

The concepts had to be compared based on a boundary layer analysis and a flow separation model.  After careful consideration, XFlow, from Next Limit Technologies, was chosen to perform the boundary layer analysis.  XFlow features the highest fidelity Wall-Modeled Large Eddy Simulation (WMLES) approach to the turbulence modeling.  The software was used to perform a 3D analysis of the pressure distribution over the vehicle.

Side wind has a significant influence on the drag when driving around a track, so to investigate how much the drag changes the concepts were investigated under different sideslip angles.  By using the results of a low turbulence wind tunnel test, the XFlow model could be analyzed even further.  The insights that we gained by using Rescale were very valuable when planning the wind tunnel test.

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XFlow Velocity simulation over Ecorunner body

 

To get the results, the Nickel hardware configuration was used.  This core type with 128 cores was the most cost-effective configuration for our simulations.  This resulted in a reliable boundary layer analysis.  It proved to be a very good tool to research iterations and compare concepts.  The next step for us is to implement rotating wheels into the model.

The use of Rescale saved us valuable time and money.  It also made a boundary layer analysis possible.  This has never been done in our design process.  By doing the analysis we were able to investigate the different concepts in detail before making a choice and further iterate the model, leading to an even more efficient hydrogen powered car.

About Eco-Runner Team Delft:
Eco-Runner Team Delft is a multi-disciplinary student team at Delft University of Technology. The goal of the team is to build an super efficient vehicle that runs on hydrogen. The team participates in the Shell Eco-Marathon, in May 2015 the team won the race with an efficiency of 3653 km per energy equivalent of a liter of gasoline. For more information on the team and its achievements please visit www.ecorunner.nl

This article was written by Eco-Runner Team Delft.