| Zugriffsnummer | 15301 |
| Dokumenttyp | Konferenzartikel |
| Peer Review | unbekannt |
| Sprache | Englisch |
| Titel | Spatial-resolved velocity measurements of shear flows with a novel differential Doppler velocity profile sensor |
| Autor(in); Institution |
Czarske, Jürgen; Laserzentrum Hannover e.V. (LZH), Laser Metrology, Hannover, GERMANY
Büttner, Lars; Laserzentrum Hannover e.V. (LZH), Laser Metrology, Hannover, GERMANY
Razik, T.; Laserzentrum Hannover e.V. (LZH), Laser Metrology, Hannover, GERMANY
Müller, Harald; 1.31, Strömungsmesstechnik, PTB-Braunschweig
Dopheide, Dietrich; 1.3, Fluidmechanik, PTB-Braunschweig
Becker, Stefan; Universität Erlangen-Nürnberg, Lehrstuhl für Strömungsmechanik (LSTM), Erlangen, GERMANY
Durst, Franz; Universität Erlangen-Nürnberg, Lehrstuhl für Strömungsmechanik (LSTM), Erlangen, GERMANY
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| Quelle/Jahr | 11th International Symposium on Applications of Laser Techniques to Fluid Mechanics:(2002), 12 S. |
| Availability | [CD-ROM] ; file name: paper_21_1.pdf |
| Verlag | Lisboa: Instituto Superior Técnico - IST |
| Konferenzangaben | 11th International Symposium on Applications of Laser Techniques to Fluid Mechanics, Lisboa, 08-11, July, 2002, Portugal |
| Freie Schlagworte | Differential doppler technique ; velocity profile sensor ; shear flows |
| Zusammenfassung | A measuring system based on a differential laser-Doppler velocimeter has been extended to determine one-dimensional velocity profiles of shear flows with a spatial resolution in the micrometer range. The principle of the realised velocity profile sensor is based on two-wavelength fringe systems with different gradients of their fringe spacings. After wavelength-sensitive detection two Doppler frequencies are determined, which yield the position as well as the velocity component of individual tracer particles. Conventional one-point laser Doppler velocity measurements suffer from a poor spatial resolution defined by the size of the measurement volume. Strong gradients of flows can not be resolved. Also stationary flows have to be assumed, since a traversing is necessary. The profile sensor offers the advantage that no mechanical scanning is needed to obtain flow velocity profiles over a length of up to 5 mm. In the centre of the measurement volume a spatial resolution of 1.6 μm results. The velocity profile sensor thus provides a tool for highly spatially resolved measurements of shear flows with strong velocity gradients. Shear flow measurements were performed at wind tunnels at PTB and LSTM. Figure 1 shows spatial-resolved velocity measurements of laminar shear flows in flat-plate boundary layers. A good agreement with the Blasius velocity profile was obtained. The velocity profile sensor can be applied for the measurement of instationary flows in pipes as well as for highly-resolved velocity profile measurements of flows in micro-channels or micro-nozzles. |
Zitierung
Czarske, J., Büttner, L., Razik, T., Müller, H., Dopheide, D., Becker, S., & Durst, F. (2002). Spatial-resolved velocity measurements of shear flows with a novel differential Doppler velocity profile sensor. 11th International Symposium on Applications of Laser Techniques to Fluid Mechanics, Lisboa, 08-11, July, 2002, Portugal.