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Maybe I missing lots here, but I don't really see the distinction
between the soldiers marching on the bridge, and the bow on the violin
string.
The only difference is that in the violin case, the magnitude
of the stimulation is probably large, and so many modes of vibration on
excited, and a few selected, whereas in the soldier case, the
stimulation is weak so only the one mode of vibration is excited.
> Type-1. (A) I hang a spring pendulum from an electromagnetic driving coil
> (such as Pasco-scientific SF-9324 or WA-9753) and I drive the coil with an
> oscillator and find that a certain driving frequency causes build-up of
huge
> oscillations in the spring pendulum. (B) I sing a short-duration steady
> pitch into my piano with the damper pedal depressed and upon stopping
> singing note that a particular string(s) has been excited.
> Type-2. (C) I strike a tuning fork with a rubber mallet and note that the
> fork vibrates at particular frequencies.
(D) I bow a violin string and note
> the string vibrates with particular frequencies. (E) I blow across the top
> of a soda-pop bottle and note that I produce particular frequencies of
> sound.
vortex shedding is determined by the frequency of the torsional
oscillation of the bridge; it is not inherent in the wind.
This is not the phenomenon usually referred to as (von Karmann)
vortex shedding.