XFV

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X-ray Flow Visualization

 

Research Goal
The long-term goal of this research effort is to perform noninvasive three-dimensional X-ray imaging of large-scale multiphase flows to study and characterize industrial-scale multiphase flow processes.

Background
Gas-liquid, gas-solid, liquid-solid, and gas-liquid-solid multiphase flows are difficult to visualize, characterize, and quantify because the systems are typically opaque. Invasive or noninvasive measurement methods are typically used for determining internal flow and transport characteristics of these complex flows. The difficulty with invasive methods is that they can alter the internal flow of a multiphase system causing interference with realistic process measurements. X-ray imaging provides one family of noninvasive measurement techniques used extensively for product testing and evaluation of static objects with complex structures. These techniques have been extended to visualize dynamic systems, such as those which characterize multiphase flows.

Our research uses a one-of-a-kind X-ray flow visualization facility (called the ISU XFloViz facility) to acquire digital X-ray images of large-scale multiphase flows. The XFloViz facility is affectionately referred to as a “lead tree house” because the imaging room is located 12 ft off the laboratory floor and lined with 9 tons of lead to contain the X-ray radiation. In addition to digital X-ray radiography capabilities, the imaging system allows for X-ray computed tomography (i.e., CT scans) of multiphase flows in large vertical systems, providing time-averaged local phase distributions. We are also using the X-ray imaging system to develop a novel application of X-ray stereography and stereographic reconstructions to visualize time-resolved flow structures in three dimensions.

Funding Sources

  • National Science Foundation
  • Iowa State University
Major Equipment

XFlowViz Facility (Picture | Schematic)

X-ray Imaging Platform (Picture)

Vertical Lift (Picture)

LORAD LPX200 portable x-ray unit (2 units) (Picture)

DVC-1412 CCD camera connected to a 16” diameter Precise Optics PS164X image intensifier (2 sets) (Picture)

Apogee Alta U9 CCD camera connected to a 44 x 44 cm cesium-iodide scintillator screen
(link to picture when available)

Static Objects Sample Results
Air-filled tubes immersed in water (Picture)Loaf of bread (Picture)Cob of corn (Picture)

Dynamic Processes Sample Results

Ground corncob bed
Ug = 1.1Umf (video)
Ug = 1.3Umf (video)
Ug = 1.5Umf (video)

Glass bead bed
Ug = 1.1Umf (video)
Ug = 1.3Umf (video)
Ug = 1.5Umf (video)

Melamine bed
Ug = 1.1Umf (video)
Ug = 1.3Umf (video)
Ug = 1.5Umf (video)

Ground walnut shell bed
Ug = 1.1Umf (video)
Ug = 1.3Umf (video)
Ug = 1.5Umf (video)

Tracer particle studies
KI-doped corn kernel tracers in melamine bed at half speed
Polypropylene/solder spherical tracer in glass bead bed at half speed
Polypropylene/solder spherical tracer in glass bead bed at half speed
Polypropylene/solder spherical tracer in sand bed at half speed
Ag coated polypropylene spherical tracers in melamine bed

Ground corncob bed
Ug = 1.5Umf, no side air (Qs = 0Qmf) at half speed (video)
Ug = 1.5Umf, Qs = 0.10Qmf at half speed (video)
Ug = 3Umf, no side air (Qs = 0Qmf) at half speed (video)
Ug = 3Umf, Qs = 0.10Qmf at half speed (video)

Glass bead bed
Ug = 1.25Umf, no side air (Qs = 0Qmf) at half speed (video)
Ug = 1.25Umf, Qs = 0.10Qmf at half speed (video)
Ug = 1.5Umf, no side air (Qs = 0Qmf) at half speed (video)
Ug = 1.5Umf, Qs = 0.10Qmf at half speed (video)
Ug = 1.5Umf, Qs = 0.10Qmf at half speed (colored) (video)
Ug = 3Umf, no side air (Qs = 0Qmf) at half speed (video)
Ug = 3Umf, Qs = 0.10Qmf at half speed (video)
Ug = 3Umf, Qs = 0.10Qmf at half speed (colored) (video)

Ground walnut shell bed
Ug = 1.5Umf, no side air (Qs = 0Qmf) at half speed (video)
Ug = 1.5Umf, Qs = 0.10Qmf at half speed (video)
Ug = 3Umf, no side air (Qs = 0Qmf) at half speed (video)
Ug = 3Umf, Qs = 0.10Qmf at half speed (video)

Test 1 (video)
Test 1 (colored) (video)
Test 2 (video)
Test 3 (video)
Test 4 (video)
Glass marble in H = 1 in. melamine
15 Hz (video)
35 Hz (video)

KI-doped corn kernel in H = 1 in. ground walnut shell
15 Hz (video)
35 Hz (video)

Glass marble in H = 1 in. ground walnut shell
15 Hz (video)
25 Hz (video)
35 Hz (video)

Polypropylene/solder sphere in H = 1 in. ground walnut shell
15 Hz (video)
35 Hz (video)

Glass marble in H = 2 in. ground walnut shell
15 Hz (video)

Superficial Gas Velocity Ug = 1 cm/s
Water only, Ug = 1 cm/s
10% PEG, Ug = 1 cm/s
20% PEG, Ug = 1 cm/s
30% PEG, Ug = 1 cm/s
40% PEG, Ug = 1 cm/s
50% PEG, Ug = 1 cm/s
50% PEG, Ug = 1 cm/s

Superficial Gas Velocity Ug = 2 cm/s
Water only, Ug = 2 cm/s
10% PEG, Ug = 2 cm/s
20% PEG, Ug = 2 cm/s
30% PEG, Ug = 2 cm/s
40% PEG, Ug = 2 cm/s
50% PEG, Ug = 2 cm/s

Superficial Gas Velocity Ug = 3 cm/s
50% PEG, Ug = 3 cm/s

Picture of 21 cm ID STR

Qg = 9 LPM, N = 350 RPM (loaded conditions)
Digital picture
x-slice CT through tank center
z-slice CT 0.8 cm from base of impeller
z-slice CT 3.0 cm from base of impeller
z-slice CT 5.3 cm from base of impeller
z-slice CTs stacked to make video

Qg = 9 LPM, N = 700 RPM (completely dispersed conditions)
Digital picture
x-slice CT through tank center
z-slice CT 0.8 cm from base of impeller
z-slice CT 3.0 cm from base of impeller
z-slice CT 5.3 cm from base of impeller
z-slice CTs stacked to make video

Two-dimensional wave
Colored two-dimensional wave (slowed 4x)
Spouted bed sequence
Spouted bed video
Air burp radiograph
Air burp X-ray video
Particle tracer movie
Diaper adsorption
Water filling a shell macaroni bed
Colored water filling a shell macaroni bed
Water filling a rice bed
Colored spouted bed video
Rising loaf of bread sequence
Rising loaf of bread dual video
Rising loaf of bread side view video
Rising loaf of bread end view video
X-ray video of air flow in 0.1% by weight cellulose fiber suspension
X-ray video of air flow in 1% by weight cellulose fiber suspension
Sequence of air flow in 1% by weight cellulose fiber suspension
CT slices of air flow in cellulose fiber suspensions
Local gas holdup in fiber suspensions