Water moving around a cylindrical pendulum makes the cylinder swing at the vortex shedding frequency.
When fluid flows around a cylindrical object, there is a range of flow velocities for which a von Karman vortex street is formed. The...
A thin wire, moving through the air, is made to vibrate in the audio range at the vortex shedding frequency.
When air flows around an object, there is a range of flow velocities for which a von Karman vortex street is formed. The shedding...
Standing sound waves in a glass pipe are made evident by the fountains of kerosene inside the pipe.
The air inside a very large glass pipe (partially filled with a fluid) is acoustically excited into a standing wave. Once resonating, the...
For a body to reach terminal velocity when falling through a fluid, the drag force (given by Stoke's Law) coupled with the buoyant force (from Archimedes' principle) need to balance the falling object's weight. Leaving derivations to other...
Ink is squirted into a fluid and mixed in until it disappears. By precisely undoing the motions in the reverse direction, the ink becomes unmixed! The demonstration seems to defy thermodynamics in that it appears that entropy decreases...
Bernoulli's Principle states that the pressure exerted by a fluid is velocity dependent; the faster the velocity the lower the pressure. This can be demonstrated by a form of Venturi tube, a pipe with a narrow constriction which forces an...
Bernoulli's principle shows the velocity dependence of pressure in a fluid. Here, fast flowing air creates a zone of low pressure that holds a beach ball aloft.
He...
The relative velocities of two sides of a spinning ball to an oncoming wind creates a pressure difference and therefore a net force on the ball perpendicular to the air flow.
figure 1. Direction of motion of ball due to pressure difference
James Clerk Maxwell postulated that since heat involves the movement of molecules, it might be possible to separate hot and cold air in a device with the help of a "friendly demon" who would sort out and separate the fast and slow moving...
