Imaging methods in multi-phase flow research

advertisement
Experimental fluid dynamics at
Department of the Energy and Process
Engineering,
Tampere University of Technology
Pentti Saarenrinne
13th Oct 2011
Dept. of Energy and Process Engineering
Figures
•
•
•
•
Budget 3,6 M€ (1,7 +1,9 M€)
7 professors
30 researchers & research
assistants
6 technicians
Research topics
•
•
•
•
Fluid Mechanics & Heat Transfer
(CFD & Experimental)
Paper converting and packaging
Refrigeration Technology
Combustion & Power Plant
Technology
The EFD group
The group is specialized in optical measurement
techniques in fluid mechanics and their adaptation to multiphase flows.
Other research topics include turbulence, fluid-structure
interactions, flow control, and mixing.
The team:
• Pentti Saarenrinne, Professor, D. Sc. (Tech)
• Hannu Eloranta, D. Sc. (Tech.) moved to Pixact Ltd
• Markus Honkanen, D. Sc. (Tech.)
• Maria Putkiranta, M.Sc. (maternity leave)
+ M.Sc. students
Measurement facilities
For single-phase flows
• PIV (three systems, including
high-speed SPIV)
• LDA
For multi-phase flows
• Direct imaging (high-speed &
others)
• PDA
The laboratory has several water
circulation loops, mixing tanks…
Paper converting laboratory
• Pilot plant (1 m width)
• Laboratory
Fiber suspension flows
Simultaneous PIV and DI in a dilute fiber suspension flow
Fiber suspension flows
Simultaneous PIV and DI in a dilute fiber suspension flow
Fiber orientation and flocculation
measurements
Experiments are conducted…
The flow setup
Fiber orientation measurements
The effect of fiber consistency...
C=0.02%-w
C=0.1%-w
C=0.5%-w
Fiber orientation measurements
The flocculation experiments
•
•
Pine, 0.5%-w (mean length: 2.3mm, crowding factor: ~60)
Two flow rates: 2.25 l/s (Uexit=5.0m/s) and 4.00 l/s (Uexit=8.5m/s)
•
Two channels
Data collection
• Images of the fiber phase were collected with two backlighting systems:
• Double-frame camera operating at 4 Hz
• High-speed camera operating at 1000-4000 Hz
Floc orientation
Mean floc size scale and aspect ratio
Bubble analysis with 3D orthogonal imaging
• Rising bubbles, frame rate 1000
1/s .
• Orthogonal projections of the
flow was achieved with a mirror
system.
• Automatic image analysis
recognises bubbles, even when
they are overlapping.
.
Ink removal from recirculated
pulp suspension
-
Measurements in a flotation
tank
Submerged probe for the
bubble size distribution in the
inlet jet.
Image analysis
Air removal from fiber suspension in an open
channel flow
• Submerged measurement device
sinking in suspension .
•Bubble movement in a fiber
suspension.
•Blue broken lines are bubble
path lines.
The strain distributions inside a year ring during
sudden compression in a split-Hopkinson device
Objectives:
• To develop an imaging and illumination method for the phenomena
• The preparation of the wood samples to enable the measurement of the
deformation inside a year ring
• Measurement were made at elevated temperatures in a closed splitHopkinson device at Mid-Sweden University (Sundsvall).
The strain distributions inside a year ring in sudden
compression /2
With frame rate 50 000
1/s was imaged in one
Compression a serie of 12 images.
Results:
• From the deformation images was computed strain maps.
• The year rings of the sample are on the right hand side of the large
strain areas.
• The deformation in the ”spring” wood is bigger
A Laboratory Scale CFB
H x W x D: 3.0 x 0.4 x 0.015 m.
Cold model.
Fluidization velocities up to 4.0 m/s.
Sauter mean diameters: 442 μm or 255 μm.
•Particle size distribution was measured with
shadowgraphy:
High speed imaging at the bottom part of
the model
Frame rate300Hz
Red arrow, velocity
upwards 5 m/s,
 Blue arrow same velocity
downwards
testi image nr. 0
0
2.1
4.2
y [mm]
6.3
8.4
10.5
12.6
14.6
16.7
18.8
0
4.2
8.4
12.6
16.7
20.9
25.1
x [mm]
testi-f16 image nr. 1
0
y [mm]
5
10
15
20.1
0
10
20.1
30.1
x [mm]
40.1
50.2
60.2
Thank you for your attention!
Download
Random flashcards
Arab people

15 Cards

Radioactivity

30 Cards

Create flashcards