Kelvin-Helmholtz in My House
This is a classic Kelvin-Helmholtz instability, captured as one of about 400 frames I took of water vapor falling from my decorative humidifier this evening. The last time I tried this, I didn't have a flash, so it just didn't work very well. But now I have one, and so I used it to backlight the falling water vapor. I set my camera to take one frame every four seconds, and let it rip until the card filled up! This is significantly better than my first attempt at this.
The K-H instability arises when one layer of gas or fluid is moving past another. The velocity difference can give rise to regular oscilations at the boundary between the two layers, and sometimes these oscillations become a K-H instability, showing the classic curlyques at regular intervals. They typically don't last long, as they're very sensitive to conditions. If anything changes, the instability disintigrates immediately, and assumes either a more gentle gravity wave form or a much more chaotic turbulent form. But when things are just right, this lovely pattern emerges. This pattern can be seen in the clouds, though rarely, particularly above mountains where faster moving air is being forced to rise to get over the mountain, where it meets a layer of more slowly moving air.
Emergence: chaotic fluid flow occasionally organizes in seemingly non-chaotic ways, which are fragile and fleeting, having initial condition sensitivity.
Kelvin-Helmholtz in My House
This is a classic Kelvin-Helmholtz instability, captured as one of about 400 frames I took of water vapor falling from my decorative humidifier this evening. The last time I tried this, I didn't have a flash, so it just didn't work very well. But now I have one, and so I used it to backlight the falling water vapor. I set my camera to take one frame every four seconds, and let it rip until the card filled up! This is significantly better than my first attempt at this.
The K-H instability arises when one layer of gas or fluid is moving past another. The velocity difference can give rise to regular oscilations at the boundary between the two layers, and sometimes these oscillations become a K-H instability, showing the classic curlyques at regular intervals. They typically don't last long, as they're very sensitive to conditions. If anything changes, the instability disintigrates immediately, and assumes either a more gentle gravity wave form or a much more chaotic turbulent form. But when things are just right, this lovely pattern emerges. This pattern can be seen in the clouds, though rarely, particularly above mountains where faster moving air is being forced to rise to get over the mountain, where it meets a layer of more slowly moving air.
Emergence: chaotic fluid flow occasionally organizes in seemingly non-chaotic ways, which are fragile and fleeting, having initial condition sensitivity.