Flow-Field Surveys Behind Three Squareback Car Models Using a New “Fourteen-Hole” Probe 870243
The flow-field mapping technique previously developed in the Pininfarina wind tunnel has further evolved during 1986.
The former technique (1985), based on the use of a “seven-hole” probe, had two main limitations:
poor sensitivity at low speed (<8 m/sec.)
incapability of measuring at flow angles greater than +− 70°
Both these conditions often occur inside the near-wakes of passenger-car models.
Therefore, wake maps (velocities and pressures) made in the past were largely incomplete in their inner parts.
The new probe has a double “seven-hole” pattern and its performance exceeds that of two “seven-hole” probes used separately.
It was developed during the fourth year of a research program aimed at providing new experimental information on reverse flows in automobile wakes, for use in developing improved computational fluid dynamic (CFD) techniques for automobiles.
Reverse flows inside the near-wake of three full-scale squareback car models were investigated.
One of these models is the same as was tested in the past. The other two differ slightly in their rear-end shape from the first one.
The main characteristics of the new probe and its performance are presented and compared with the “seven-hole” probe.
Furthermore, the maps of velocities and pressures measured in the wakes of the three squareback car models are reported.