Synchrotron X-ray multi-projection imaging (XMPI) for high-resolution 4D characterization of multiphase flows

Area of Science:

• Multiphase flow dynamics
• Microparticle imaging
• Biomedical engineering

Background:

• Observing microscale dynamics in opaque multiphase flows is challenging.
• Existing methods struggle with visualizing particles in non-transparent fluids.
• Critical processes in biology, medicine, and geophysics involve these flows.

Purpose of the Study:

• To introduce a novel imaging technique for 4D tracking of microparticles in opaque flows.
• To overcome limitations of current methods for visualizing microscale dynamics.
• To enable experimental validation of computational models for complex suspensions.

Main Methods:

• Developed Synchrotron X-ray Multi-Projection Imaging (XMPI).
• Utilized simultaneous X-ray projections from multiple angles without sample rotation.
• Applied to individual particle tracking velocimetry (3D PTV) and multi-projection image velocimetry.

Main Results:

• Achieved 4D (3D + time) tracking of microparticles in opaque fluids like blood.
• Resolved instantaneous particle positions and trajectories.
• Demonstrated capabilities in both dilute and dense suspensions.

Conclusions:

• XMPI provides unprecedented experimental validation for particle-resolved CFD models.
• Enables observation of inertial focusing and microstructural dynamics.
• Opens new avenues for high-resolution 4D imaging of complex multiphase flows.