Quantifying the dynamics of flow within a permeable bed using time-resolved endoscopic particle imaging velocimetry (EPIV)
- 810 Downloads
This paper presents results of an experimental study investigating the mean and temporal evolution of flow within the pore space of a packed bed overlain by a free-surface flow. Data were collected by an endoscopic PIV (EPIV) technique. EPIV allows the instantaneous velocity field within the pore space to be quantified at a high spatio-temporal resolution, thus permitting investigation of the structure of turbulent subsurface flow produced by a high Reynolds number freestream flow (Re s in the range 9.8 × 103–9.7 × 104). Evolution of coherent flow structures within the pore space is shown to be driven by jet flow, with the interaction of this jet with the pore flow generating distinct coherent flow structures. The effects of freestream water depth, Reynolds and Froude numbers are investigated.
KeywordsPore Space Light Sheet Flow Depth Pore Flow Laser Endoscope
We thank the UK Natural Environment Research Council for funding this work (NE/E006884/1). All experiments were undertaken in the Ven Te Chow Hydrosystems Laboratory, University of Illinois, and we thank Professor Marcelo Garcia for allowing access to this facility, and Professor Kenneth Christensen for providing part of the PIV equipment. Stephan Kallweit of Intelligent Laser Applications (ILA GmbH) supplied the endoscopes and much useful advice on their application, for which we are very grateful.
Online Resource 1 Sequence of images of instantaneous flow fields showing the evolution of flow driven by a downstream jet leading to formation of a vortical pathway. Supplementary material 1 (AVI 22777 kb)
Online Resource 2 Sequence of images of instantaneous flow fields showing the evolution of flow triggered by a spanwise jet leading to formation of a large vortical structure, whose evolution is driven by fluid motion that is first downstream and then upstream. Supplementary material 2 (AVI 6537 kb)
- Best JL, Kirkbride A, Peakall J (2001) Mean flow and turbulence structure in sediment-laden gravity currents: new insights using ultrasonic Doppler velocity profiling. In: McCaffrey WD, Kneller BC, Peakall J (eds) Particulate gravity currents, special publication of the international association of sedimentologists, vol 31. Blackwell Science, Oxford, UK, pp 159–172. doi: 10.1002/9781444304275.ch12
- Dybbs A, Edwards RV (1984) A new look at porous media fluid mechanics. Darcy to turbulent. In: Bear J, Corapcioglu MY (eds) Fundamentals of transport phenomena in porous media. Martinus Nijhoff Publisher, NATO ASI Series, Series EGoogle Scholar
- Forchheimer P (1901) Wasserbeweguing durch Boden. Z Ver Deutsch Ing 45:1782–1788Google Scholar
- Klar M, Jehle M, Jahne B, Detert M, Jirka GH, Kohler HJ, Wenka T (2004) Simultaneous 3-D PTV and micro-pressure sensor equipment for flow analysis in a subsurface gravel layer. In: Greco M, Carravetta A, Della Morte R (eds) Proceedings of the 2nd international conference on fluvial hydraulics. Napoli, Italy, pp 703–712Google Scholar
- Nield DA, Bejan A (2006) Convection in porous media, 3rd edn. Springer, New York. ISBN 978-0387-29096-6Google Scholar
- Raffel M, Willert CE, Wereley ST, Kompenhans J (2007) Particle image velocimetry: a practical guide, 2nd edn. Springer, BerlinGoogle Scholar