TY - CHAP
A1 - Nakagawa, Masaki
A1 - Michaux, Frank
A1 - Kallweit, Stephan
A1 - Maeda, Kazuhiro
T1 - Unsteady flow measurements in the wake behind a wind-tunnel car model by using high-speed planar PIV
T2 - 11TH International Symposium on Particle Image Velocimetry – PIV15 Santa Barbara, California, September 14-16, 2015
N2 - This study investigates unsteady characteristics of the wake behind a 28%-scale car model in a wind tunnel using highspeed planar particle image velocimetry (PIV). The car model is based on a hatchback passenger car that is known to have relatively high fluctuations in its aerodynamic loads. This study primarily focuses on the lateral motion of the flow on the horizontal plane to determine the effect of the flow motion on the straight-line stability and the initial steering response of the actual car on a track. This paper first compares the flow fields in the wake behind the above mentioned model obtained using conventional and high-speed planar PIV, with sampling frequencies of 8 Hz and 1 kHz, respectively. Large asymmetrically coherent flow structures, which fluctuate at frequencies below 2 Hz, are observed in the results of highspeed PIV measurements, whereas conventional PIV is unable to capture these features of the flow owing to aliasing. This flow pattern with a laterally swaying motion is represented by opposite signs of cross-correlation coefficients of streamwise velocity fluctuations for the two sides of the car model. Effects of two aerodynamic devices that are known to reduce the
fluctuation levels of the aerodynamic loads are then extensively investigated. The correlation analyses reveal that these devices indeed reduce the fluctuation levels of the flow and the correlation values around the rear combination-lamp, but it is found that the effects of these devices are different around the c-pillar.
Y1 - 2015
ER -
TY - CHAP
A1 - Nakagawa, Masaki
A1 - Kallweit, Stephan
A1 - Michaux, Frank
A1 - Hojo, Teppei
T1 - Typical Velocity Fields and Vortical Structures around a Formula One Car, based on Experimental Investigations using Particle Image Velocimetry
T2 - SAE International Journal of Passenger Cars - Mechanical Systems
Y1 - 2016
U6 - http://dx.doi.org/10.4271/2016-01-1611
SN - 1946-4002
ER -
TY - CHAP
A1 - Kleine, Harald
A1 - Kallweit, Stephan
A1 - Michaux, Frank
A1 - Havermann, Marc
A1 - Olivier, Herbert
T1 - PIV Measurement of Shock Wave Diffraction
T2 - 18th International Symposium on Applications of Laser Techniques to Fluid Mechanics, 2016, Lissabon
Y1 - 2016
SP - 1
EP - 14
ER -