Vibration of Air Column

Topic Content:

Open Pipes:

This is a pipe open at both ends. When air is blown into the pipe, a stationary wave is set up. At the two open ends of the pipe, antinodes are formed.

For f₀ , l =  \( \frac{\lambda}{2}\)

λ = 2l

V = fλ

f = \( \frac{V}{\lambda} \)

f₀ =   \( \frac {V}{\lambda} = \frac{V}{2l}\)

In an open pipe, the possible overtones are f₀ , 2f₀ , 3f₀ , and 4f₀ , i.e. it contains both odd and even harmonics.

Closed Pipes:

These are pipes that are closed at one end. When air is blown into the pipe, the travelling wave is reflected at the closed end. The closed end is always a node and the open end an antinode.

f₀ =   \( \frac {V}{\lambda} = \frac{V}{4l}\)

A closed pipe only contains odd harmonics.

End Correction:

When a tuning fork is used to set the air column into vibration, the