This paper reports recent developments made at Pininfarina in the aeroacoustic field with the aim of reducing the background noise in the test section of its full scale wind tunnel as well as for improving the measuring techniques which are used during the acoustic development of new cars.
The first part of the paper describes the changes made to the wind tunnel drive-line, i.e. new motor, new low-noise fan and new acoustic treatments.
The new background noise levels are reported and compared with the old values, already published in ref. (2).
The second part describes the three acoustic techniques (acoustic intensimetry, acoustic holography and acoustic mirror) which have been developed or improved in the meantime, to measure the exterior noise of new cars from the first stage of their design.
Examples of results of these measurements are reported as well as an indication of the capabilities and limitations of each technique.