ISSN:
1432-1114
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract Nonintrusive measurements in a sediment-laden flow using two laser-based techniques, Discriminator Laser-Doppler Velocimetry (DLDV) and Particle Tracking Velocimetry (PTV), are compared. DLDV was previously developed at the Iowa Institute of Hydraulic Research, while PTV was specially configured for this application. Mean and fluctuating velocity components for both flow fractions were simultaneously measured in a laboratory-scale, submerged water jet loaded with alluvial sand. This information cannot be obtained using existing measurement techniques. The jet Reynolds number was 6120, and the sediment sieve diameter ranged from 0.5 to 0.6 mm. Small mass loadings of sand with inertial time constant τ p of 0.6 ms were examined. The configuration, operation, and results obtained using the DLDV and PTV are presented. For each technique, means to precisely distinguish between the light scattered by suspended sand and that originating from seed-particles following the water were implemented. The agreement in measurement for the two methods validates one another since they are based on completely different principles of operation. The capabilities of DLDV and PTV to reliably measure sand and water velocities in sediment-laden flows are further indicated by the agreement of the present findings with those obtained previously in similar studies. The comparison suggests that PTV, due to its whole field nature, could become a powerful tool for flow and particle-related diagnostics, yielding fundamental information in an area with a long history of conflicting experimental evidence.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s003480050174
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