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A Two-Component Fiber-Optic LDV System for Automotive Aerodynamics Research
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Abstract
A laser velocimeter of a new type has been recently installed in Che Pininfarina full-scale automotive wind tunnel.
Conventional laser velocimeters have been confined, up to now, to small facilities due to various difficulties which arise when measurements are to be made in large facilities.
A first important feature of the new system is that a fiber-optic link carries the laser beams from the laser generator and the main optical system located outside the test section to a small end-probe. This probe then focuses the laser beams at the measuring point, receives the backscattered light and sends it back through another fiber to a photomultiplier.
As the probe is small and lightweight, it can be easily traversed by the conventional wind tunnel traversing system.
Safety problems are greatly reduced, as beam power is lower and focal distance is short.
The new system has the capability of measuring local velocities (two components) simultaneosly and turbulence at those points of a flow field where conventional mechanical probes cannot provide reliable values.
A second important feature is the new signal processor which greatly improves the capability of the LDV in conditions of very low seeding and low signal-to-noise ratio, which are typical of full-scale wind tunnels.
This paper shows the new LDV system, its main capabilities and its limitations.
Some examples of measurements carried out with this system are also outlined.
Authors
Citation
Cogotti, A., "A Two-Component Fiber-Optic LDV System for Automotive Aerodynamics Research," SAE Technical Paper 880252, 1988, https://doi.org/10.4271/880252.Also In
References
- Cogotti, A. “A passenger car wake survey using coloured isopressure maps” Third International Symposium on Flow Visualization Ann Arbor September 1983
- Cogotti, A. “Wake surveys of different car body shapes with coloured isopressure maps” SAE paper 840229 February 1984
- Cogotti, A. “Rappesentazione delle scie di autovetture mediante mappe a colori di iso-pressioni” Pubblicazioni tecniche e scien-tifiche del PFT Angeli Franco April 1984
- Cogotti, A. “Nuove tecniche di misura nella galleria del vento” ATA October 1985 vol. 38 n. 10
- Cogotti A. “Car wake imaging using a seven-hole probe” SAE paper 860214 February 1986
- Cogotti, A. “Evoluzione nelle tecniche per la mappatura di pressioni e velocita' in galleria del vento” Pubblicazioni tecniche e scientifiche del PFT Angeli Franco November 1986
- Cogotti, A. “Recent advances in flow field mapping techniques” SAE paper 870718 , Auto-technologies Montecarlo 87 January 1987
- Cogotti, A. “Flow field surveys behind three squareback car models using a fourteen-hole probe” SAE paper 870243 February 1987
- Cogotti, A. “Pininfarina Wind Tunnel- Status Report 1987” EADE Meeting Paris October 1987
- DANTEC Laser Doppler Anemometry 1983
- TSI Laser Velocimetry Systems 1986
- Buchheim, R. Durst, F. Beeck, M.A. Hentschel, W. Piatek, R. Schwabe, D. “Advanced experimental techniques and their application to automotive aerodynamics” SAE paper 870244 February 1987
- Reinath M.S. “Long range laser velocimeter for use in NFAC facilities” Palo Alto, SATA meeting June 1987
- Kaufman, S.L. Fingerson L.M. “Fiber Optics in LDV Applications” International Conference on Laser Anemometry Manchester 1985
- DANTEC A New Era in Signal Processing -The Burst Spectrum Analyzer 1987