X-ray-based flow visualization and measurement: application in multiphase flows

Area of Science:

• Multiphase flow dynamics
• Non-intrusive measurement techniques
• X-ray imaging applications

Background:

• Understanding continuous and discreet phase flow in multiphase systems is crucial for many applications.
• Optical methods for multiphase flow analysis are limited by refraction indices and void fraction, especially in opaque liquids.
• X-ray-based techniques offer a promising alternative due to their penetration capabilities and independence from optical properties.

Purpose of the Study:

• To demonstrate the potential of X-ray-based methods for multiphase flow visualization and measurement.
• To present two novel non-intrusive X-ray techniques for analyzing bubble column flows.
• To highlight the advantages of X-rays over optical methods in challenging multiphase systems.

Main Methods:

• X-ray-based particle tracking velocimetry (PTV) was employed to measure the 3D velocity field of the continuous liquid phase in a bubble column using seeded particles.
• X-ray visualization of liquid flow was achieved by injecting an X-ray absorbing liquid tracer into the bubble column.
• Both methods utilized X-rays for their ability to penetrate multiphase systems without distortion.

Main Results:

• Successful measurement of the 3D liquid phase velocity field in a bubble column using X-ray PTV.
• Effective visualization of liquid flow patterns within the bubble column using X-ray absorption.
• Demonstrated independence of X-ray methods from void fraction and applicability to opaque liquids.

Conclusions:

• X-ray-based techniques are highly effective for non-intrusive multiphase flow analysis.
• These methods overcome limitations of optical techniques, offering broader applicability in systems like bubble columns.
• X-ray imaging provides valuable data for practical and analytical applications involving complex fluid dynamics.