Upgrade of the full-scale aeroacoustic wind tunnel of Stuttgart University by FKFS

Abstract

FKFS has operated the full-scale aeroacoustic wind tunnel of University of Stuttgart for many years. One task is to keep this wind tunnel as one of the most modern ones of its kind. In 2014, the wind tunnel has again been upgraded significantly. The aerodynamic as well as the aeroacoustic performance have been improved significantly and the operational processes have been accelerated. Also new innovative features have enlarged the test capabilities to a significant extent. A new modular belt system (FKFS first®), which is patented, allows high performance measurements in a 3-belt mode e.g. for race cars as well as precise and efficient measurements for production vehicle development in a 5-belt mode. A new, larger turntable houses the belt system and a new under-floor balance which enables highaccuracy measurements of forces and moments also for a high resolution in time. Parasitic forces which are generated at the wheel drive units, are eliminated by a specific correction procedure which is also patented (FKFS pace®). The enhanced road simulation is rounded up by a new type of boundary layer conditioning system. A unique, active side wind generator (FKFS swing®) enables investigations of unsteady aerodynamics and aeroacoustics. It consists of 8 wing-like profiles with independent drives which can deflect the whole airflow around the car in the test section with a frequency of up to 10 Hz. Acoustic linings in the first diffuser and other measures have improved the acoustic performance of the wind tunnel. Low frequency pulsations of the open jet are suppressed very efficiently by special patented profiles in the nozzle (FKFS besst®) and a Helmholtz resonator. The profiles also reduce the high-frequency noise of the wind tunnel.