Browse Publications Technical Papers 2022-01-0891
2022-03-29

Experimental and Numerical Investigation of Rim Aerodynamics 2022-01-0891

The automotive industry is facing new emission regulations, changing customer preferences and technology disruptions. All have in common, that external aerodynamics plays a crucial role to achieve emission limits, reduce fuel consumption and extend electric driving range. Probably the most challenging components in terms of numerical aerodynamic drag prediction are the wheels. Their contribution to the overall pressure distribution is significant, and the flow topology around the wheels is extremely complicated. Furthermore, deltas between different rim designs can be very small, normally in the range of only a few drag counts. Therefore, highly accurate numerical methods are needed to predict rim rankings and deltas.
This paper presents experimental results of four different production rim designs, mounted to a modified production car. An accurate representation of the loaded, deformed tire geometry is used in all calculations for comparable conditions between wind tunnel and CFD. Different simulation approaches are compared and analyzed to measured rim rankings and deltas. A special meshing strategy is introduced to reduce the influence of mesh changes on the flow field to a minimum.
A steady state simulation approach in combination with a moving reference frame model is able to capture the delta between the best and worst rim design. The rim position has a non-negligible influence when using this frozen rotor method and needs to be considered. Transient scale resolving simulations with real motion of the rims remove the limitations of steady state. Ranking and deltas are accurately predicted for all four rims by the simulations.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Preview Document Add to Cart
Members save up to 16% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:
TECHNICAL PAPER

Numerical Analysis of Aerodynamic Impact on Passenger Vehicles during Cornering

2018-37-0014

View Details

TECHNICAL PAPER

External Flow Analysis Over a Car to Study The Influence of Different Body Profiles Using CFD

2001-01-3085

View Details

TECHNICAL PAPER

Optimization of the Aerodynamic Lift and Drag of LYNK&CO 03+ with Simulation and Wind Tunnel Test

2020-01-0672

View Details

X