1998-02-23

Experimental Investigation into Unsteadiness and Instability in Passenger Car Aerodynamics 980391

Flow unsteadiness has been investigated experimentally for two idealised model geometries including the Ahmed form. Several techniques were used including twin hot-wire probes located at different positions in the wake and a frequency domain correction method for pneumatic tubing. Levels of periodicity in the wakes and on the surfaces of the models have been examined using spectral analysis techniques. Unsteadiness was found to originate from movement of the closed separation bubble at the end of the large radii at the front of the models and from vortex shedding when large radius curved rear surfaces are present.

SAE MOBILUS

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

Access SAE MOBILUS »

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

Unsteady-Wake Analysis of the Aerodynamic Drag of a Notchback Model with Critical Afterbody Geometry

920202

View Details

JOURNAL ARTICLE

Flow Structures above the Trunk Deck of Sedan-Type Vehicles and Their Influence on High-Speed Vehicle Stability 1st Report: On-Road and Wind-Tunnel Studies on Unsteady Flow Characteristics that Stabilize Vehicle Behavior

2009-01-0004

View Details

TECHNICAL PAPER

The Ahmed Model Unsteady Wake: Experimental and Computational Analyses

2003-01-1315

View Details

X