Two-dimensional particle displacement tracking in particle imaging velocimetry

Area of Science:

• Fluid dynamics
• Experimental fluid mechanics
• Image processing

Background:

• Particle imaging velocimetry (PIV) is crucial for fluid flow analysis.
• Existing PIV systems face limitations in data acquisition and processing speed.
• Accurate and rapid velocity vector determination is essential for understanding complex flows.

Purpose of the Study:

• To develop and test a novel, high-speed particle imaging velocimetry data acquisition and analysis system.
• To introduce an all-electronic technique for particle displacement tracking (PDT).
• To demonstrate the system's capability in measuring 2-D velocity vectors efficiently.

Main Methods:

• Developed a particle displacement tracking (PDT) system using a video camera and a large memory buffer frame-grabber.
• Implemented a simple encoding scheme to time-code a sequence of single exposure images into a single image.
• Processed the time-coded image to track particle displacements and calculate 2-D velocity vectors.

Main Results:

• The new PDT system is an order of magnitude faster than previous systems.
• Successfully generated over 1100 velocity vectors in 110 seconds using an 80386 PC.
• Validated the system's performance in a counterrotating vortex flow.

Conclusions:

• The developed PDT system offers a significant advancement in PIV technology, enabling faster data acquisition and analysis.
• The all-electronic, single-image processing approach provides an efficient method for determining 2-D velocity vectors.
• This technique holds potential for broader applications in experimental fluid mechanics requiring high-speed flow measurements.