K-H Instability

Making a current speed difference
at the density boundary layer

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(a)


(Animation gif)
2 layers

(b)



2 layers

(c)



3 layers

Once the velocity difference exceeds the critical value,
the boundary layer becomes unstable and the two fluids mix.

Experimental conditions

Density difference:(a,b) 0.05g/cm3 ; (c) 0.025g/cm3 respectively.
The photos in (a) were taken at 0.2 second intervals, starting a few seconds after the tank was tipped.

Photographic conditions

f=50mm, F2, 1/1000 sec, ASA100, a motor drive was used.

Filming conditions

Real time recordings.
240x180: 15 fps, 320x240: 30 fps.