Full-Volume 3D Fluid Flow Reconstruction With Light Field PIV

Area of Science:

• Fluid Dynamics
• Computer Vision
• Optical Measurement

Background:

• Particle Imaging Velocimetry (PIV) traditionally estimates fluid flow by tracking particles.
• Reconstructing and tracking dense, occluded particles in 3D is a significant computer vision challenge.

Purpose of the Study:

• To develop a low-cost, high-resolution 3D Particle Imaging Velocimetry (PIV) system.
• To enable accurate full-volume 3D fluid flow reconstruction using novel optimization algorithms.

Main Methods:

• Utilized compact lenslet-based light field cameras for particle imaging.
• Developed optimization algorithms for dense particle 3D reconstruction and tracking.
• Employed a two-camera system with orthogonal positioning to compensate for depth resolution limitations.
• Fused multi-view particle data using a linear assignment problem (LAP) with anisotropic point-to-ray distance.
• Applied physically-constrained optical flow for full-volume 3D fluid flow recovery.

Main Results:

• Achieved high-resolution 3D particle reconstruction in the full fluid volume.
• Demonstrated superior accuracy with two-view reconstruction compared to single-view.
• Successfully recovered full-volume 3D fluid flows of various types from synthetic and real data.
• Validated the effectiveness of novel optimization algorithms for dense particle tracking and flow analysis.

Conclusions:

• The proposed low-cost light field camera PIV system offers a robust solution for challenging 3D fluid flow measurement.
• The two-view approach effectively overcomes single-camera depth resolution limitations, enabling accurate volumetric reconstruction.
• This method advances the capabilities of PIV for detailed analysis of complex fluid dynamics.