Scaling analyses of high-resolution dye tracer experiments
Författare
Summary, in English
Four unsaturated solute transport experiments with different water fluxes were conducted in a Hele-Shaw cell filled with uniform sand. The transport of the dye tracer used was recorded with a camera and the dye concentration was calculated using image analysis. The concentrations fields were analysed in terms of time moments and converted into vertical solute transport velocity V. Both mean value and standard deviation of V increased with water flux. The autocorrelation function exhibited a linear decrease for short lags. The pronounced variability of V suggested a description in terms of scaling properties, and a scaling regime was indeed found from the resolution 1.8 mm up to almost 0.1 m. The upper limit corresponds roughly to a characteristic scale of fingering structures seen in the dye concentration images. Indications of a second scaling regime at larger scales were found. In the small-scale scaling regime, the power spectrum exponent beta was generally slightly below 1 and the intermittency parameter C-1 was on average 0.00025. The moment scaling K-q functions were convex, implying a multiscaling process.
Avdelning/ar
Publiceringsår
2008
Språk
Engelska
Sidor
1286-1299
Publikation/Tidskrift/Serie
Hydrological Sciences Journal
Volym
53
Issue
6
Dokumenttyp
Artikel i tidskrift
Förlag
Taylor & Francis
Ämne
- Water Engineering
Nyckelord
- scaling analysis
- solute transport
- dye tracer
- power spectrum
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 0262-6667