turbulence in the system of two immiscible liquids
DESCRIPTION
Turbulence in the system of two immiscible liquids. Petr Denissenko, Sergei Lukaschuk, Sergei Poplavski. Laboratory of Fluid Dynamics, The University of Hull. The study was initiated by the work Misha Chertkov, Igor Kolokolov, Vladimir Lebedev, U. of Warwick, September 15, 2005. - PowerPoint PPT PresentationTRANSCRIPT
Turbulence in the system of two immiscible liquids
Petr Denissenko, Sergei Lukaschuk, Sergei Poplavski
Laboratory of Fluid Dynamics, The University of Hull
Suspensions of immiscible liquids
We study Energy spectra of two flows:
Flow 1: silicon oil (=3, =0.88)
Flow 2: 80% oil + 20% water-glycerol (60% water, 40% glycerol, =3, =1.1)
Surface tension on the oil-mixture interface = 0.04 N/m. Water-glycerol is coloured by fluorescent dye Rhodamine 6G.
Additional scale: capilary length
Industrial applications: mixing, suspension formation
L
0r
0r
l
The study was initiated by the work
Misha Chertkov, Igor Kolokolov,Vladimir Lebedev, U. of Warwick, September 15, 2005
French Washing Machine 9×9×12 cm withCounter-rotating two-blade propellers.
CCD camera 2048x2028 pixeladapted from PIV
Nd YAG pulsed laser, Green, 532 nm
LDA probeBlue, 476 nm
LDA greenBlue, 514 nm
Water-Glycerol mixture visualized by fluorescent dye Rhodamine 6G (yellow)
2-point Velocity measurement by Laser Doppler Anemometer
Water-Glycerol (white) mixing with oil (black)
image27 x 27mm
Pumping scaleL = 60 mm
Capillary scalelc = 10 mm
Viscous scale = 0.3 mm
Same refractive indexSame dynamic viscositySame density (not yet)
Refractive index and viscosity (3 10-3 Pas) are matched between Silicone Oil and Water-Glycerol phases by adjusting Water-to-Glycerol proportion (40% Glycerol) and the Temperature (37°C).
Density may be matched by choosing the composition of Silicone Oil
French Washing Machine 9×9×12 cm withCounter-rotating two-blade propellers.
CCD camera 2048x2028 pixeladapted from PIV
Nd YAG pulsed laser, Green, 532 nm
LDA probeBlue, 476 nm
LDA greenBlue, 514 nm
Water-Glycerol mixture visualized by fluorescent dye Rhodamine 6G (yellow)
2-point Velocity measurement by Laser Doppler Anemometer
Camera image
Droplets chosen for FFT analysis
Measurement of droplet size and shape
Decomposition of the bubble shape by circular harmonics
Mode energyMode am
plitude
Mode number
Note! We analyze a section, not the 3D shape.
3 rps4 rps5 rps6 rps8 rps
Distribution of droplets by diameter
3 rps4 rps5 rps6 rps8 rps
Distribution of WG volume by droplet diameter
Position of maximum
2222
2
3
4)(
harmonicper ndeformatio surface ofEnergy
droplet per Energy Surface
2/
/2 /
dropleta on wavecapillary a offrequency and Length
nnnndeformatio
surface
n
anakdE
dE
kf
dnknd
Each harmonic at each droplet is assigned the Wavelength, the Frequency, the Energy.
E= d2
Distribution of surface energy by droplet diameter
E= 4 n2an2
Distribution of oscillations energy by droplet diameter
Position of maximum in energy distribution by droplet size
3 rps4 rps5 rps6 rps8 rps
Energy of oil droplets versus energy of fluid
E3/5
5/35/32
5/3
2
3/2
3322
EVE
V
Ll
l
L
L
llNlE
ls
L
s
French Washing Machine 9×9×12 cm withCounter-rotating two-blade propellers.
CCD camera 2048x2028 pixeladapted from PIV
Nd YAG pulsed laser, Green, 532 nm
LDA probeBlue, 476 nm
LDA greenBlue, 514 nm
Water-Glycerol mixture visualized by fluorescent dye Rhodamine 6G (yellow)
2-point Velocity measurement by Laser Doppler Anemometer
Laser Doppler AnemometryMoving particle crosses the interference pattern on the intersection of laser beams. Modulation of reflected light gives the particle velocity.
. . . . . . .
. . . . . .
. . . . . . ..
Problems: Laser beams are deflectedParticles are leaving the fluid volume to the droplet surface
. ..
..
....
..
... .. .
...
.... . .... ...
-4
6 rps5 rps4 rps3 rps
Thick lines: oil onlyThin lines: oil and Water-Glycerol mixture
LDA measurement of energy spectrum in single-phase and two-phase flows
LDA measurements:energy spectrum in pure oil and
in oil + 20% Water-Glycerol mixture
V/lc V/lc
rV
||
Two-point measurements:velocity correlation in pure oil and
with 20% of Water-Glycerol mixture
Distance between probes, mm
Cor
rela
tion
coe
ffic
ient
rV
SummarySuspension of two immiscible liquids of a similar viscosity is studied.
Droplet shapes are resolved within the suspension.LDA measurements are conducted within the suspension.
Distribution of droplet size and energy spectra of droplet oscillations are measured.Distorsion of energy spectra of fluid motion due to capillary effects is detected.Ratio of surface energy to kinetic energy is measured.
Future plansMatch the fluid densities.
Resolve the spectra below capillary scale.
Perform the two-point LDA measurement of structure functions.