On-road Turbulence 2008-01-0475

The turbulent environment experienced by ground vehicles is currently not well understood. Due to this, and other historical reasons, the aerodynamic testing of automobiles is usually conducted in extremely low-turbulence wind tunnels (<1%), which is in clear contradiction with the small amount of wind data available to date for these heights. This work presents a series of turbulence measurements made in a range of different on-road terrains and traffic conditions. This data was captured using multi-hole pressure probes mounted to the front of a test vehicle traveling at a road speed of 100 km/h. Analysis of the data shows how both the turbulence intensities and turbulent length scales are modified by terrain type, road side obstacles and the upstream wakes of other moving vehicles