| Zugriffsnummer | 24973 |
| Dokumenttyp | Konferenzartikel |
| Peer Review | unbekannt |
| Sprache | Englisch |
| Titel | Self calibrating FSK-Doppler Global Velocimetry for three-componential time resolved and phase averaged flow field measurements |
| Autor(in); Institution |
Eggert, Michael; 1.4, Gase, PTB-Braunschweig
Müller, Harald; 1.4, Gase, PTB-Braunschweig
Czarske, Jürgen; TU Dresden, Department of Electrical Engineering and Information Technology, Dresden, GERMANY
Büttner, Lars; TU Dresden, Department of Electrical Engineering and Information Technology, Dresden, GERMANY
Fischer, Andreas; TU Dresden, Department of Electrical Engineering and Information Technology, Dresden, GERMANY
|
| Quelle/Jahr | 15th International Symposium on Applications of Laser Techniques to Fluid Mechanics:(2010) |
| Availability | [online] |
| URL | |
| Verlag | Heidelberg [u.a.]: Springer |
| Konferenzangaben | 15th International Symposium on Applications of Laser Techniques to Fluid Mechanics, Lisbon, 05-08, July, 2010, Portugal |
| Freie Schlagworte | DGV ; self calibrating ; time resolved ; phase resolved ; flow field analysis |
| Zusammenfassung | By applying frequency shift keying (FSK) to the Doppler Global Velocimetry, it is possible to omit the reference camera which usually is required in conventionally used DGV systems. Additionally frequency shift keying realized by well defined frequency steps of the laser used for the light sheet generation in the measuring plane allows an absolute online calibration of the Doppler shift evaluation in the over-all DGV set-up for the velocity field analysis. Thus the uncertainty of velocity field measurements can be reduced and the absolute velocity measurement accuracy increases. Based on the application of frequency shift keying to the emission frequency of the lightsheet generating laser, the Doppler shift of the scattered light is evaluated by analyzing image sequences. The well defined frequency steps allow an online calibration including seeding density and absorption cell influences as well as the camera characteristics for each individual pixel. Furthermore it is possible to perform time resolved velocity field measurements with a spatial and temporal resolution depending on the resolution and frame rate of the CCD camera and the available laser power in the laser light sheet. Applying the self-calibrating FSK technique to time resolved velocity measurements on a spinning disc, standard deviations down to 0.25 m/s and absolute deviations below 0.21 m/s were achieved for velocities up to approximately 30 m/s considering only single CCD camera pixels. Time resolved measurements of a steady flow field show a standard deviation of about 0.6 m/s, while the standard deviation in 100 temporally binned measurement cycles is reduced down to about 0.06 m/s. Phase resolved measurements in the wake of a finite cylinder demonstrate the capability of this technique to suppress systematic influences in long-term measurements. |
Zitierung
Eggert, M., Müller, H., Czarske, J., Büttner, L., & Fischer, A. (2010). Self calibrating FSK-Doppler Global Velocimetry for three-componential time resolved and phase averaged flow field measurements. 15th International Symposium on Applications of Laser Techniques to Fluid Mechanics, Lisbon, 05-08, July, 2010, Portugal.