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Density Current Laboratory

The Density Current Laboratory is a dedicated laboratory space for
the design and measurement of sediment-laden and solute gravity current experiments.

An outline of the facilities within the DCL are below, including the specifications for each and outputs from the previous projects that have utilised them.

If you'd like more information please get in touch with Gareth Keevil.

Contact Details for Quote and Availability

Dr Gareth Keevil

Email: g.m.keevil@leeds.ac.uk

Twitter : @SEE_Fluids_UK

Large Flume Tanks

T-Tank

This is a T-shaped deep flume primarily designed to investigate density currents, both solute and particulate. This flume offers excellent visualisation and can be adapted with a wide range of inserts to change the experimental geometry. Input and output pumps are designed to balance, thus maintaining a constant water depth during experiments.

T Tank

  • The main experimental section of the T-tank is approximately 8 x 1.8 x 1.5 m (width x length x depth), and the input channel has a length of ~1.2 m.
  • The experimental surface is 1.5 m2, raised to generate a sump space that is approximately 0.45 m above the bottom of the tank.
  • The entire tank can be tilted up to 3° and the input channel slope can also be raised independently up to 3°.
  • The tank is supplied by a pair of 1800 litre mixer tanks, yielding a maximum dense fluid volume of 3600 litres, although an experiment typically uses ~200-500 litres. The mixers can suspend sediment up to 200 µm and a maximum concentration of 10%.
  • The dense fluid is pumped in via a bronze centrifugal pump with a maximum flow rate of ~7 l/s, the rate is monitored by an electromagnetic flowmeter.
  • The tank output is pumped via a second bronze centrifugal pump with a maximum flow rate of ~7 l/s, the rate is monitored by an electromagnetic flowmeter.
  • There is a 200 litre header tank and mixer that can suspend sediments up to ~ 200 µm this can be fed from the mixers to maintain a constant gravity controlled flow rate this feed, the absolute rate can be varied between 0.1-5 l/s and is also monitored via an electromagnetic flowmeter.
  • A computer controlled X-Y traverse system that can be used with a range of depth tools to provide bathymetry measurements.

Re-circulating Flume

This a classic open channel recirculating flume that can recirculate water or clay suspensions. This flume is suitable of a wide range of applications including classic bedform experiments with a mobile bed, high concentration bedform experiments and wide range of open channel configurations. The flume offers good visualisation of both fluid flow and bedform development.

Recirculating Flume Bedforms Isabel de Cala

Sediment Bed Desposit

  • The main section of the flume is approximately 3 x 8.5 x 0.3 m (width x length x depth) with a maximum fill depth of 0.275 m.
  • The channel can be tilted up to ~ 1° slop
  • The channel is recirculated by an open impeller Hidrostal pump with a maximum flow rate of 100 l/s. The rate can varied infinitely via a Danfoss inverter. This pump can recirculate clean water and sediment suspensions up to 50% volume (Kaolin).
  • The flow rate can be monitored by an electromagnetic flowmeter.
  • The pump has a high level – low level protection circuit which automatically stops the pump if the water level rises or falls. This makes this flume suitable for long duration unattended experiments.
  • The tank also has a X-Y computer controlled traverse system (4 m length) that can be used with a range of depth tools to provide bathymetry measurements with both clear water and high concentration flows.

Large Scale Density Current Tank

The Large Scale Density Current Tank is designed to host large scale experiments either stream table type fluvial experiments or large-scale expanding density currents.

  • The main section of the flume is approximately 2.5 x 10 x 1 m (width x length x depth).
  • The tank is supplied by a 2000 litre mixer tank, with a variable speed paddle mixer.
  • The dense fluid is pumped in via a stainless steel centrifugal pump with a maximum flow rate of ~14 l/s, the rate is monitored by an electromagnetic flowmeter. The input geometry is designed to flexible allows relocation of the input source.
  • This tank can also be set-up to recirculate water and fine sediment from the output end to input via a pair of 1000 litre settling/stilling tanks.
  • The tank has a 2.5 by 2.5 m computer controlled X-Y traverse system.

Small Flume Tanks

Lock Exchange Flume

Small lock-exchange flume designed to run repeatable fixed volume density currents.

Lock Exchange Flume

  • The main section of the flume is approximately 2 x 5 x 0.25 m (width x length x depth)
  • The lock system is flexible hosting up to 3 gates. The volume of each lock is variable by 0.125 m increments, up to a maximum length of 1 m.
  • The gate(s) are lifted using pneumatic rams, the rate lift is variable. The timing of gate activation can be controlled electronically.
  • The main tank is supplied from a single 1800 litre mixer tank, this enable the use of saline and stratified ambient.
  • Solute fluid is prepared in 200 litre mixing tank, this tank has both a rotary mixer and recirculation pump and low turbulence fluid transfer pump.
  • Automated mixers can be added within lock-boxes to suspend sediment, these automatically switch off at the gate is removed.

Thin Recirculating Flume

This is primarily a teaching flume used to demonstrate bedform growth and development in unidirectional flow.

  • The main section of the flume is approximately 0.05 x 1.5 x 0.2 m (width x length x depth).
  • The channel can be tilted up to ~ 3° slope.
  • The tank is recirculated by a variable speed stainless steel pump. The rate can varied infinitely via an inverter.
  • This flow can recirculate water and sediment either directly or via a stilling tank.

Instrumentation

Ultrasonic Velocity Profilers (UVP)

This is a doppler velocity profiling system that measures fluid velocity on a single axis.

  • Measurements are made via individual transducers, these can be used individually or in sets.
  • Each measurement profile is variable (between 2-256 bins) and the length of the profile can also be varied, as a function of the flow velocity and concentration.
  • The transducers have a fixed frequency of 0.5, 1, 2, 4, or 8 MHz, up to 10 transducers can be multiplexed to enable flow mapping.
  • UVPs exhibit excellent signal penetration in high concentration flows and are suitable for mapping flows in complex bounding geometries.

Acoustic Doppler Velocimeters (ADV)

This is a doppler velocity profiling system that utilises a single emitter and four receiving transducers with a fixed geometry.

ADV in bubble tank

  • This instrument can be set to use either one or multiple measurement bins. When using multiple this enables the measurement of a short velocity profile (40-70 mm) from the transmitter.
  • This system records 3-components of velocity at up to 100 Hz, it also records the water depth beneath the emitter.
  • This system is best suited to making high-resolution measurements of boundary layers when used in profiling mode. Or can be used as a single point ADV in a wide range of settings.

Focused Beam Reflectance Measurement (FBRM)

This instrument has a unique capability; measuring in situ particle size and number characteristics.FBRM Measuring Particulate Density Current

  • This is an optical system that records the count and chord length of any particles that pass its recording window. This generates a chord length population at 0.5 Hz.
  • The measurement is made at the end of a stainless steel probe (diameter 25mm, length 500 mm).
  • The measurement range is between 0.5-2000 µm.
  • Chord length is proportional to particle diameter and can be inverted when measuring spherical particles.

 

Particle View and Measurement (PVM)

This instrument comprises a high speed, high resolution camera on the end of 20 mm stainless steel probe.

  • It records a series of images or video.
  • LED illumination enables visualisation of particles in dense suspensions.
  • The PVM is an idea partner to the FBRM to provide both size and shape characteristics.

Peristaltic/Sample Pumps

Peristaltic PumpA range of peristaltic pumps is available with flow rates of 50-0.01 l/min.

  • High capacity pumps are ideal for transferring high-viscosity fluids.
  • Multichannel pumps are available for sampling particle suspensions.

Cameras

A range of dSLR cameras are available for recording still, high definition video images and time-lapse.

  • A wide range of lens is available from macro to telephoto.
  • A colour highspeed camera (HS resolution up to 1000 fps) is available, this can record up to 12 GB of images in a single capture.
  • LED lighting is available to illuminate small and large areas.

Small Instruments

  • A range of optical and acoustic concentration meters, a handheld density meter and conductivity probes is also available.
  • Digital slope meters and precision levels are available for levelling models and flumes.
  • The lab has a suit of processing computers for visualising quantitative data and processing photos and videos.
  • Online storage is available for data storage and back-up.

Sediment storage and mixing

  • There is dedicated room for wetting and mixing fine powdered sediments. This rooms contains high volume extraction and is designed for total wash down.
  • A forklift truck enables simple transport and organisation of bulk sediment deliveries.
  • Storage is available for pallets of dry material.
  • A mobile mixer is available to allow preparation and transport of sediment slurries

Articles Which Include Data Collected in DCL and Using DCL Instrumentation

Publications

Rice, H.P., Peakall, J., Fairweather, M., and Hunter, T.N., Extending Estimation of the Critical Deposition Velocity in Solid-Liquid Pipe Flow to Ideal and Non-Ideal Particles at Low and Intermediate Solid Volume Fractions, Chemical Engineering Science, Vol. 211, No. 1, 115308, 2020.

 

Rice, H.P., Fairweather, M., Hunter, T.N., Mahmoud, B.H., Biggs, S.R., and Peakall, J., Measurement of Particle Concentration in Settling Multiphase Pipe Flow Using Acoustic Methods, Proceedings of the 10thInternational ERCOFTAC Symposium on Engineering Turbulence Modelling and Measurements – ETMM10, Marbella, Spain, 17th-19th September 2014.

 

Rice, H.P., Fairweather, M., Peakall, J., Hunter, T.N., Mahmoud, B.H., and Biggs, S.R., Constraining the Functional Form of the Critical Flow Velocity at Low Concentrations in Multiphase Pipe Flow, Turbulence, Heat and Mass Transfer 8, Proceedings of the Eighth International Symposium on Turbulence, Heat and Mass Transfer, Sarajevo, Bosnia and Herzegovina, 15th-18th September 2015, Hanjalic, K., Miyauchi, T., Borello, D., Hadziabdic, M., and Venturini, P. (Eds.), Begell House Inc., New York, pp. 579-582, 2015.

 

Hugh P. Rice, Jamie L. Pilgrim,  Michael Fairweather, Jeff Peakall, David Harbottle, Timothy N. Hunter (2020) Extending acoustic in-line pipe rheometry and friction factor modeling to low-Reynolds-number, non-Newtonian slurries. AIChE J. 2020;e16268.

Davarpanah Jazi, S., Wells, M.G., Peakall, J., Dorrell, R.M., Thomas, R.E., Keevil, G.M., Darby, S.E., Sommeria, J., Viboud, S., Valran, T., 2020. Influence of Coriolis force upon bottom boundary layers in a large-scale gravity current experiment: Implications for evolution of sinuous deep-water channel systems. Journal of Geophysical Research – Oceans, 125, e2019JC015284, doi: 10.1029/

Bux, J, Peakall, J, Rice, HP et al. (2019) Measurement and density normalisation of acoustic attenuation and backscattering constants of arbitrary suspensions within the Rayleigh scattering regime. Applied Acoustics, 146. pp. 9-22.

Ho, V. L., Dorrell, R. M., Keevil, G. M., Thomas, R. E., Burns, A. D., Baas, J. H., & McCaffrey, W. D. (2019). Dynamics and Deposition of Sediment-Bearing Multi- Pulsed Flows and Geological Implication. Journal of Sedimentary Research, 8(11), 1127-1139.

Kelly, R. W., Dorrell, R. M., Burns, A. D., & McCaffrey, W. D. (2019). The structure and entrainment characteristics of partially-confined gravity currents. Journal of geophysical research. C, Oceans, 124(3), 2110-2125.

Ho, VL, Dorrell, RM, Keevil, GM et al. (2018) Pulse propagation in turbidity currents. Sedimentology, 65 (2). pp. 620-637

Ho, V. L., Dorrell, R. M., Keevil, G. M.,Burns, A. D., & McCaffrey, W. D. (2018). Scaling analysis of multipulsed turbidity current evolution with application to turbidite interpretation.Journal of Geophysical Research:Oceans, 123

Dorrell RM, Amy LA, Peakall J, McCaffrey WD. 2018. Particle Size Distribution Controls the Threshold Between Net Sediment Erosion and Deposition in Suspended Load Dominated Flows. Geophysical Research Letters. 45(3), pp. 1443-1452

Creelle, S., Thomas, R. E., Schindfessel, L., McLelland, S. J., Creëlle, S., & De Mulder, T. (2017). Bias in mean velocities and noise in variances and covariances measured using a multistatic acoustic profiler: the Nortek Vectrino Profiler. Measurement Science and Technology, 28(7), 075302.

Baas, J.H., Best, J.L., Peakall, J., 2016a. Predicting bedforms and primary current stratification in cohesive mixtures of mud and sand. Journal of the Geological Society, 173, 12-45. doi: 10.1144/jgs2015-024.

Peakall, Jeff ; Sumner, Esther J (2015) Submarine channel flow processes and deposits: A process-product perspective Geomorphology, 01 September 2015, Vol.244, pp.95-120

Peakall, Jeff ; Sumner, Esther J (2015) Submarine channel flow processes and deposits: A process-product perspective Geomorphology, 01 September 2015, Vol.244, pp.95-120

Fletcher, T., Altringham, J., Peakall, J., Wignall, P., Dorrell, R., 2014. Hydrodynamics of fossil fishes. Proceedings of the Royal Society B 281,

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