Fluid Dynamics Laboratory

The Fluid Dynamics Laboratory (FDL) excels in the quantification of complex geophysical flows using Particle Imaging Velocity (PIV) techniques. An outline of the facilities within the FDL 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

Instrumentation

Volumetric PIV

Volumetric PIV allows measurements of fluid velocity within a volume (3D), rather than a plane (2D) as measured by standard PIV systems. This is a 100 Hz system comprising 4 cameras and can be configured for either laser or LED illumination.

 

  • Illumination from either 100 Hz dual cavity 100mJ laser or 300 W LED array.
  • Four highspeed Vision Research cameras that can be flexibly configured according to the experimental geometry.
  • Processing software can use either a tomographic reconstruction or a particle tracking approach (Shake-the-box) to reconstruct the data volume.
  • Dedicated 32 core processing computer with high spec GPU.

100 Hz PIV

Particle imaging velocimetry (PIV) is a technique to measure instantaneous fluid velocity. A laser light sheet illuminates seeding particles suspended in the fluid and a high-speed camera records the particle displacements. This can be configured to capture either planar or stereo data. This PIV is modular and is highly configurable to suit a wide range of applications.

  • 100 Hz dual cavity lasers both 50 and 100 mJ.
  • A selection of light sheet optics to generate lightsheets suitable for both planar and stereo PIV.
  • A pair of Vision Research monochrome cameras.
  • A wide selection of camera optics to enable a wide range of imaging.
  • This system can be configured for laser-induced fluorescence (LIF) imaging, to quantify concentration or temperature fields.
  • Dedicated 32 core processing computer.

LDA & PDA

Laser Doppler anemometry (LDA) is an absolute measurement technique that allows quantification of one, two or three components of flow within a very small measurement volume.

  • System uses three fibre coupled 1000 mW solid-state lasers for illumination.
  • Focal length is nominally 400 mm, but this can be shortened or lengthened to suit a range of experimental geometries.
  • System is highly flexible and can measure velocity from mm/s to supersonic flows.
  • The LDA can be reconfigured from backscatter mode to forward scatter mode using extra detectors to become a phase Doppler anemometer (PDA), allowing quantification of velocity and particle diameter.

High Speed Camera

The FDL has a dedicated high definition colour high speed Vision Research camera. This system can record HD images at 1000 fps.

  • High speed camera allows visualisation of short duration events.
  • Colour camera allows visualisation of multiple phases, particles or dyed fluids.
  • 12 Gb of RAM and integrated SSD allow rapid collection of multiple image ensembles.

Acoustic Instruments

The FDL shares a wide range of acoustic instruments with the density current laboratory. These instruments enable detailed quantification of opaque flows and within environments where optical access is difficult (e.g. pipes, reactors, complex geometries).

  • Ultrasonic velocity profilers (UVP) allow flow field measurements within opaque and high concentration flows.
  • UVPs can be deployed very flexibly to measure multiple flow components within complex experiments or a single transducer can be deployed for high-rate measurements.
  • Acoustic Doppler velocimeters (ADV) allow three component measurements from a wide range of flow experiments.
  • The ADVs can be used in profiling mode to measure short 3D velocity profiles or boundary measurements.

Specialist Experimental Facilities

The FDL has a range of specialist experimental facilities, designed and constructed within the laboratory. We have the capability to manufacture bespoke experimental rigs to allow the investigation and quantification of a wide range of fluid dynamic phenomena.

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, enabling 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.

Pumped Density Current Tank

This is a ducted density current flume designed specifically to enable high resolution optical measurements within density currents, using both planar and tomographic PIV. The flume is designed to accommodate a range of refractive index matched fluids.

  • The main section of the flume is approximately 1 x 2.5 x 0.2 m (width x length x depth), with an additional sump and air traps.
  • The slope can be varied between 0-2°.
  • The experimental area is ducted to remove the effect of surface waves.
  • The tank is fed by a constant rate positive displacement gear pump. This pump is suitable for use with a range of refractive index matched fluids. The rate can be varied infinitely via an inverter.
  • A pair of mixing tanks enable the preparation of refractive index matched fluids

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 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 vary infinitely via an inverter.
  • This flow can recirculate water and sediment either directly or via a stilling tank.
  • PIV (either laser or LED illuminated) can be used with this flume for high resolution bedform measurements.

Decagonal Tank

This is a settling tank designed to enable the deployment of the tomographic PIV system. The tank is designed to enable both laser and LED illumination with optical access for four cameras.

  • Integrated mounts for four cameras and either laser or LED illumination
  • Remote control system for releasing particles for settling studies.
  • Tank designed to accommodate 2-layer PIV targets, as required by tomographic PIV.
  • Integrated recirculation and system to suspend seeding material. Filter system allows rapid fluid replacement whilst capturing seeding materials

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.

Hugh P. Rice et al. (2015) Particle concentration measurement and flow regime identification in multiphase pipe flow using a generalised dual-frequency inversion method Procedia Engineering 102, pp. 986 – 995

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

Fletcher T, Altringham J, Peakall J, Wignall P, Dorrell R. (2014) Hydrodynamics of fossil fishes. Proceedings of the Royal Society B: Biological Sciences. 281(1788)

Chalk C, Pastor M, Peakall J, Borman D, Sleigh PA, Murphy W, Fuentes R. (2020) Stress-Particle Smoothed Particle Hydrodynamics: an application to the failure and post-failure behaviour of slopes. Computer Methods in Applied Mechanics and Engineering.

C. J. Lloyd, J. Peakall, A. D. Burns, G. M. Keevil & R. M. Dorrell (2020) Numerical errors at walls: on the sensitivity of RANS models to near-wall cell size, International Journal of Computational Fluid Dynamics

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