Analysis of the overall accuracy in LDV measurement of film flow in an inclined channel
| Autor: | N Aksel, M Schmidtchen |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
Accuracy and precision
business.industry Applied Mathematics Reynolds number Laminar flow Mechanics Open-channel flow Physics::Fluid Dynamics symbols.namesake Cross section (physics) Optics Distribution (mathematics) Flow (mathematics) symbols business Instrumentation Engineering (miscellaneous) Mathematics Dimensionless quantity |
| Zdroj: | Measurement Science and Technology. 7:1140-1147 |
| ISSN: | 1361-6501 0957-0233 |
| Popis: | In this paper the measurement accuracy of laser-Doppler-velocimeter (LDV) measurements in film flows is discussed. Error bounds for the measured velocity can be established by direct comparison of the experimental results with an exact analytical solution for film flows in channels with rectangular cross section. The validity check of the solution is performed by comparing the film height measurements with the corresponding theoretical values. A lower limit for the error bounds of the LDV measurements is predicted for given and fixed uncertainties of the fluid and flow parameters. The dimensionless velocity distribution and the dimensionless film height in an unidirectional open channel flow depend only on the parameter k = H/B, the ratio of the classical two-dimensional film height H to the channel half width B. For increasing k the deviation between the two-dimensional theory and the analytical solution also increases. The solution is independent of the Reynolds number, provided that the flow remains laminar. Experimental results for vertical Reynolds numbers below 0.1 are presented. The experimental results are in excellent agreement with the analytical solutions. |
| Databáze: | OpenAIRE |
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