Computer-Created, Flow-Optimized SUV

How much fuel does a vehicle consume? How high are its emissions? Using the worldwide Harmonized Light Vehicles Test Procedure (WLTP), the necessary measurements are performed under conditions that are as realistic as possible. This includes a higher speed compared to the previous New European Driving Cycle (NEDC), a longer route, and consideration of optional extra equipment. Due to the higher speed, the influence of aerodynamics on consumption increases. This has resulted in research and development in aerodynamics becoming more important. Röchling Automotive is contributing to this with its own open source solution – AeroSUV.

The name says it all: this solution focuses on sport utility vehicles (SUVs). There is a reason for this. SUVs achieve the largest share of the global car market year after year. Using a generic SUV model for aerodynamics research is therefore particularly relevant. Against this backdrop, Röchling Automotive, together with the Research Institute of Automotive Engineering and Vehicle Engines Stuttgart (FKFS), has developed a freely accessible, neutral model in the scale 1:4. The project was presented at the Stuttgart International Symposium of the FKFS in March 2019. The geometry of the AeroSUV is available to download as an open-source solution from the website ecara.org.

Cars are complex. The spinning wheels create vortexes that interact with the rest of the airstream. Air enters at the front through the cooling air intake and exits again at various and often unexpected points on the vehicle. Generic models, like the AeroSUV, are perfect for testing new technologies as they reduce this complexity. For example, the cooling air flow can be fully suppressed. You can also remove the wheels and seal the wheel arches with foam to make the flow “simpler.” “On a generic model, at least I can exclude some of the external influences acting on the technology I am testing,” explains Dr. Juliane Nies, Aerodynamics Expert at Röchling Automotive in Worms, Germany.

Generic models also ensure better comparability. A slightly different lift and drag coefficient is measured for the same vehicle in different wind tunnels – depending on the size of the test track or the ground simulation, for example. The publicly available CAD data means the generic model can be used to perform comparative measurements between different wind tunnels. In addition to this, because the model features fewer details, numerical simulations of the flow dynamics can be performed much faster.

Although generic models are already available on the market, they are either not an SUV model or are not an open-source solution. The AeroSUV is therefore the next step on from DrivAer – a generic car model – in the expansion of the platform of open-source models. The idea behind an open-source model is that everyone publishes their measurements and simulation results, meaning that all other users can use them for comparison purposes against their own measurements and to verify their simulations.

Röchling Automotive and the scientific community now have the option of performing simulations easily, realistically and quickly using AeroSUV. This means innovative ideas can be tested quickly. The AeroSUV not only creates a neutral database, but also enables new fields of innovation to be accessed quickly.

 
 

Dr. Ing. Juliane Nies

Röchling Automotive, Aerodynamics Expert

Advanced Development Aerodynamics & New Mobility

Phone: +49 6241 844-236

juliane.nies@roechling-automotive.de

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