Particle tracking velocimetry

Particle Tracking Velocimetry, or PTV for short, is a method to see how things move. Think about it like watching a river. You can see how fast the water is moving in the center vs. at the edges, or if there is anything floating in the water that is getting carried downstream. PTV does the same thing, but instead of looking at water, it looks at tiny particles that are too small to see with your eyes.

First, we need to collect the particles. These are usually small and lightweight, like tiny beads. We put them in the fluid we want to measure, like water or air. When the fluid moves, the particles move with it.

Next, we take a picture of the particles. This is kind of like taking a photo of a bunch of ants on the sidewalk. We can see where they are and how they are moving. But instead of looking at one photo, we take many photos very quickly. This lets us see how the particles move over time.

Finally, we use software to analyze the pictures. The software looks at each particle in the pictures and tracks where it goes. This lets us figure out how fast the particles (and the fluid around them) are moving in different directions. It's kind of like watching ants move in different directions on the sidewalk and figuring out which way they're going.

PTV is useful for lots of things, like studying how air moves around an airplane wing or how water flows through a pipe. It helps us understand how fluids move and how we can make things move more efficiently.