Recent Advances in Flow Field Mapping Techniques 870718
Flow field mapping techniques have been regarded with great interest in recent years. They are an important tool for investigating flow characteristics around new car models during their development in the wind tunnel.
A short summary of previous techniques developed by Pininfarina, since 1982, is reported. Latest developments are then shown, which include:
A new probe, capable of measuring local pressures and velocities both in straight and reverse flows. It utilizes a “fourteen-hole” pattern which overcomes most of the limitations previously found with “seven-hole” probes.
The upgrading of the wind tunnel traversing system, both in its hardware and software components.
Probe traversing velocities up to 120 mm/sec are now commonly used during the pressure data acquisition.
Furthermore pressures and velocities may now be mapped along planar surfaces being horizontal or vertical, transversal or longitudinal, in front of, at the side of, or behind the car model.
Examples of maps plotted using the new probe and/ or the new features of the traversing system, are reported in the second half of the paper. Main indications provided by these maps are also outlined.
Finally in the appendix, the main characteristics of the updating of the Pininfarina wind tunnel to the end of 1986 are reported.
This includes changes made to the drive system, fan and other parts of the facility.