Use a dye-injection experiment (like the classic Reynolds experiment) to show a thin purple line of dye suddenly exploding into swirls as the flow speed increases.
Destin uses a parabolic mirror to visualize the hot air rising from a candle and the shockwave from a gunshot. You will "see" temperature gradients as shadows. fluid mechanics videos
Before diving into the list, it is worth understanding why video content is superior to static diagrams for this particular discipline. Use a dye-injection experiment (like the classic Reynolds
Using dyed salt water in a tank, researchers create smoke rings that collide and bounce off each other. It visualizes vorticity and conservation of angular momentum perfectly. fluid mechanics videos
3. "The Million Dollar Equation: Demystifying Navier-Stokes"