The application of sample and hold method in the processing of data obtained from a laser doppler anemometer

• Autorzy: Stelmach J. , Rzyski E.
• Języki publikacji: EN

Abstrakty

EN

Using a laser Doppler anemometer, liquid velocity was measured in the tank in which liquid was mixed by a self-aspirating disk impeller. The energy spectrum was the basis to determine the energy dissipation rate. This rate determines the size of eddies that are formed in the vicinity of the impeller. Results obtained by sample and hold method were compared with those obtained by other methods. An increase in the sampling frequency caused a decrease in the mean liquid velocity at the measuring point.

Słowa kluczowe

EN

agitation; laser Doppler anemometry; sample and hold method; energy spectrum; energy dissipation rate; self-aspirating impellers

PL

pomiary laboratoryjne; energia; wirnik

• Wydawca: Oficyna Wydawnicza Uniwersytetu Zielonogórskiego
• Czasopismo: International Journal of Applied Mechanics and Engineering
• Rocznik: 2002
• Tom: Vol. 7, no 4
• Strony: 1291--1303
• Opis fizyczny: Bibliogr. 13 poz., rys., wykr.

Twórcy

autor

Stelmach J.

• Department of Process Equipment Łódź Technical University Wólczańska 213, 93-005 Łódź, POLAND

autor

Rzyski E.

• Department of Process Equipment Łódź Technical University Wólczańska 213, 93-005 Łódź, POLAND

Bibliografia

• [1] Benedict L.H., Nobach H. and Tropea C. (1998): Benchmark tests for the estimation of power spectra from LDA signals. - Proceed, of 9th Int. Symp. on Application of Laser Technique to Fluid Mechanics, Lisbon, July 13-16, Pap. No. 32.6.
• [2] Broersen P.M.T., de Waele S. and Bos R. (2000): The accuracy of time series analysis for laser-Doppler velocimetry. - Proceed, of 10th Int. Symp. on Application of Laser Technique to Fluid Mechanics, Lisbon, 10-13 July, Pap. No. 3.4.
• [3] Costes J. and Couderc J.P. (1988): Study by laser Doppler anemometry of the turbulent flow inducted by a Rushton turbine in a stirred tank: Influence of the size of the units-II. Spectral analysis and scales of turbulence. - Chem. Eng. Sci., vol.43, No. 10, pp.2765-2772.
• [4] Gjelstrup P., Nobach H., Jprgensen F.E. and Meyer K.E. (2000): Experimental verification of novel spectral analysis algorithms for laser Doppler anemometry data. - Proceed, of 10th Int. Symp. on Application of Laser Technique to Fluid Mechanics, Lisbon, 10-13 July, Pap. No. 3.2.
• [5] Mersman A. and Laufttitte H.D. (1985): Scale-up of agitated vessels for different mixing processes. - Proceed, of 5th European Conference of Mixing, Wurzburg, 10- 12 June, Pap. No.28, pp.273-284.
• [6] Nishikawa M., Okamoto Y., Hashimoto K. and Nagata S. (1976): Turbulence energy spectra in baffled mixing vessels. - J. Chem. Eng. Japan, vol.9, No.6, pp.489-494.
• [7] Nobach H., Muller E. and Tropea C. (1998): Efficient estimation of power spectral density laser Doppler anemometer data. - Experiments in Fluids, No.24, pp.499-509.
• [8] Nobach H. (1998): A global concept of autocorrelation and power spectral density estimation from LDA data sets. - Proceed, of 9th Int. Symp. on Application of Laser Technique to Fluid Mechanics, Lisbon, 13-16 July, Pap. No. 32.5.
• [9] Nobach H. (1999): Processing of stochastic sampled data in laser Doppler anemometry. - Proceed, of 3th International Workshop on Sampling Theory and Application, SampTA’99, Loen, August 11-14, pp.149-154.
• [10] Ramond A. and Milian P. (2000): Measurements and treatment of LDA signals, comparision with hot-wire signals. - Experiments in Fluids, No.28, pp.58-63.
• [11] Siwecka K. (1996): Statistical Analysis of the Velocity Distribution in the Tank. - M.Sc. Thesis, Technical University of Łódź (in Polish).
• [12] Smith S.W. (1999): The Scientist and Engineer's Guide to Digital Signal Processing. - San Diego: California Technical Publishing.
• [13] Stelmach J. (2001): The fluctuation velocity at self-aspirating disk impeller level. - Chemical and Process Engineering, vol.22, No.3E, pp.1321-1326 (in Polish).