This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
The Aero-Acoustic Wind Tunnel of Stuttgart University
Annotation ability available
Sector:
Language:
English
Abstract
The noise emission of cruising vehicles essentially consists of tire/road noise, drivetrain noise (engine with intake and exhaust system, transmission and driving axle) and aerodynamic noise due to the flow around bodywork, chassis, wheels and cooling air flow (fan). Engines and drivetrains have become quieter due to many man-years of engineering attention and tire noise has also been reduced - at least the noise reaching the passenger compartment. Consequently, the aerodynamic noise of ground vehicles has become dominant at driving speeds above 100 kph both in interior and exterior noise.
In order to determine the contribution of aerodynamic noise to the overall noise, measurements are carried out more and more in specially equipped automotive wind tunnels. Besides wind tunnels in which aeroacoustic testing was already envisaged in the specification and design phase, existing wind tunnels can be upgraded to acoustic testing by a suitable treatment of the tunnel airpath and the plenum chamber.
The existing 22.45 m2 Open-Jet Automotive Wind Tunnel of Stuttgart University - Institute of Internal Combustion Engines and Automotive Engineering (IVK) - built in 1988 was converted into an aeroacoustic wind tunnel in 1993 by a novel silencing concept. In the return duct of this Göttingen-type wind-tunnel two U-bend silencers were installed upstream and downstream of the fan, using membrane absorbers as thin and smooth vertical splitters (for the low frequency range) in conjunction with profiling the turning vanes with coated porous Polyesterfoam (for the middle and high frequency range). An anechoic plenum chamber was achieved with a new type of broadband absorbers, mounted on the plenum walls and ceiling. Due to its very low self-noise level the IVK Aero-Acoustic Wind Tunnel provides a high potential for the acoustic rating of design optimizations in the development of future vehicles.
Recommended Content
Technical Paper | Flow Excited Noise Analysis of Exhaust |
Technical Paper | Numerical Study on the Flow Noise Generation in an Automotive Muffler System |
Technical Paper | Review of Aerodynamic Noise Prediction Using CFD |
Authors
Citation
Künstner, R., Potthoff, J., and Essers, U., "The Aero-Acoustic Wind Tunnel of Stuttgart University," SAE Technical Paper 950625, 1995, https://doi.org/10.4271/950625.Also In
References
- POTTHOFF, J. Symposium No. T-30-905-0567 1987
- HELFER, M. BUSCH, J. Contribution of Aerodynamic Noise Sources to Interior and Exterior Vehicle Noise DGLR-Workshop “Aeroacoustics of Cars” German-Dutch Wind Tunnel (DNW) Emmeloord/NL 1992
- ACKERMAN, U. MOHR, J. 1990
- OGATA, N. IDA, N. FUJI, Y. Nissan's Low Noise Full-Scale Wind Tunnel SAE Paper 870250 Detroit 1987
- LINDENER, N. STADLER, M. Symposium No. T-30-312-056-2 1992
- WIEDEMANN, J. WICKERN, G. EWALD, B. MATTERN, C. Audi Aero-Acoustic Wind Tunnel SAE Paper 930300 Detroit 1993
- ACKERMANN, U. 1990 12 457 467
- DEUTENBACH, K.-R. Influence of Plenum Dimensions on Drag Measurements in ¾ Open-Jet Automotive Wind Tunnels BMW Internal Report, 1993, and Paper planned for the 1995 SAE International Congress in Detroit
- FUCHS, H.V. ACKERMANN, U. RAMBAUSEK, N. IBP Information 14 1987 135
- WIEDEMANN, J. Written Comment to Symposium No. E”30-202-056-4 1994
- MERCKER, E. PENGEL, K. On the Induced Noise of Test Sections in Different Wind Tunnels and in the Cabin of a Passenger Car SAE Paper 940415 Detroit 1994
- DNW Annual Report 1992 German-Dutch Wind Tunnel Emmeloord/NL
- GEIB, W. LINDENER, N. th 1993
- HELFER, M. Symposium No. E-30-202-056-4 1994
- BUSCH, J. ESSERS, U. Symposium No. E-30-202-056-4 1994