Array Doppler Global Velocimeter with Laser Frequency Modulation for Turbulent Flow Analysis – Sensor Investigation and Application

  • Andreas Fischer
  • Lars Büttner
  • Jürgen Czarske
  • Michael Eggert
  • Harald Müller
Part of the Notes on Numerical Fluid Mechanics and Multidisciplinary Design book series (NNFM, volume 106)

Abstract

Velocity field measurement results of a Doppler global velocimeter (DGV) using sinusoidal laser frequency modulation are presented. Contrary to conventional DGV systems, which suffer from low temporal resolutions of several seconds, the novel DGV system allows measurement rates up to 100 kHz. The high temporal resolution is afforded by using a fibre-coupled detector array, which has a higher bandwidth than conventionally applied cameras. Additionally, low uncertainties can be achieved in contrast to conventional DGV since no second reference detector unit is necessary. The optimised set-up is capable of acquiring turbulence spectra simultaneously at multiple points. The measurement data from the wake of a cylinder agrees well with comparison measurements using hot-wire anemometry and correctly yields the Kármán vortex frequency.With the novel DGV, turbulence spectra up to about 10 kHz were resolved. Further measurement results illustrate the high potential of the described technique for non-invasive, temporally resolved, imaging flow inspection e.g. in turbomachines.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Albrecht, H.: Laser-Doppler-Strömungsmessung. Akademie-Verlag, Berlin (1986)Google Scholar
  2. 2.
    Charrett, T.O.H., Tatam, R.P.: Single camera three component planar velocity measurements using two-frequency planar Doppler velocimetry (2ν-PDV). Measurement Science and Technology 17, 1194–1206 (2006)CrossRefGoogle Scholar
  3. 3.
    Fischer, A., Büttner, L., Czarske, J., Eggert, M., Grosche, G., Müller, H.: Investigation of time-resolved single detector Doppler global velocimetry using sinusoidal laser frequency modulation. Measurement Science and Technology 18, 2529–2545 (2007)CrossRefGoogle Scholar
  4. 4.
    Fischer, A., Büttner, L., Czarske, J., Eggert, M., Müller, H.: Doppler-Global-Velozimter mit sinusförmiger Laserfrequenzmodulation zur präzisen Messung von Geschwindigkeitsprofilen. tm - Technisches Messen 73(4), 237–244 (2006)CrossRefGoogle Scholar
  5. 5.
    Fischer, A., Büttner, L., Czarske, J., Eggert, M., Müller, H.: Measurement uncertainty and temporal resolution of Doppler global velocimetry using laser frequency modulation. Applied Optics 47(21), 3941–3953 (2008)CrossRefGoogle Scholar
  6. 6.
    Fischer, A., Büttner, L., Czarske, J., Eggert, M., Müller, H.: Measurements of velocity spectra using time-resolving Doppler global velocimetry with laser frequency modulation and a detector array. Experiments in Fluids (2009) (submitted for publication)Google Scholar
  7. 7.
    Fischer, A., König, J., Büttner, L., Czarske, J., Eggert, M., Müller, H.: Messunsicherheitsschranke der Doppler-Global-Velozimetrie mit Laserfrequenzmodulation. tm - Technisches Messen 75(12), 631–640 (2008)CrossRefGoogle Scholar
  8. 8.
    Fischer, A., Czarske, J.: Signal Processing Efficiency of Doppler Global Velocimetry with Laser Frequency Modulation. Signal Processing (2009) (submitted for publication)Google Scholar
  9. 9.
    Fischer, A., König, J., Büttner, L., Czarske, J., Eggert, M., Müller, H.: Messung von Geschwindigkeitsspektren mit einem 2d3k-Doppler-Global-Array-Velozimeter mit Laserfrequenzmodulation. In: Ruck, B., Leder, A., Dopheide, D. (eds.) Lasermethoden in der Strömungsmesstechnik - 16. Fachtagung, Deutsche Gesellschaft für Laser-Anemometrie GALA e.V., Karlsruhe (2008)Google Scholar
  10. 10.
    Fischer, A., König, J., Czarske, J.: Speckle noise influence on measuring turbulence spectra using time-resolved Doppler global velocimetry with laser frequency modulation. Measurement Science and Technology 19, 125402 (15pp.) (2008)CrossRefGoogle Scholar
  11. 11.
    Jensch, M., Brede, M., Hüttmann, F., Leder, A., Frederich, O., Wassen, E., Thiele, F.: Time-Resolved Stereo-PIV Messungen im Kopfbereich und Nachlauf eines Kreiszylinderstumpfes. In: Leder, A., Brede, M., Hüttmann, F., Ruck, B., Dopheide, D. (eds.) Lasermethoden in der Strömungsmesstechnik - 15. Fachtagung, Deutsche Gesellschaft für Laser-Anemometrie GALA e.V., Rostock (2007)Google Scholar
  12. 12.
    Müller, H., Eggert, M., Czarske, J., Büttner, L., Fischer, A.: Single-camera Doppler global velocimetry based on frequency modulation techniques. Experiments in Fluids 43, 223–232 (2007)CrossRefGoogle Scholar
  13. 13.
    Pope, S.B.: Turbulent Flows. Cambridge University Press, Cambridge (2000)MATHGoogle Scholar
  14. 14.
    White, F.M.: Viscous Fluid Flow. McGraw-Hill, New York (1991)Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2009

Authors and Affiliations

  • Andreas Fischer
    • 1
  • Lars Büttner
    • 1
  • Jürgen Czarske
    • 1
  • Michael Eggert
    • 2
  • Harald Müller
    • 2
  1. 1.Department of Electrical Engineering and Information Technology, Laboratory of Measurement and Test TechniquesTechnische Universität DresdenDresdenGermany
  2. 2.Department of Gas FlowPhysikalisch-Technische BundesanstaltBraunschweigGermany

Personalised recommendations