Air Column can be found in various musical instruments where it is enclosed with a hollow metal tube. To conserve space it is coiled upon itself several times. It is almost nearer to one meter in length. Suppose if the end of the tube is left uncovered and thus allowing the sound waves to reach it then that end is termed as an open end. Various instruments operate on the mechanism of the open-end air column that is when the end of the tube are completely uncovered.
Suppose if one of the ends of the tube is left uncovered to surrounding atmosphere and another end of the tube is covered then it is termed as closed air column. For example some pipe organs and their column that is comprised within the orchestra. It is possible to convert open tube air columns to close tube air columns.
Standing Waves In Air Columns
It is a physical phenomenon where it provides sound and resonance in wind instruments. The standing wave present in air columns is nothing but a longitudinal wave or a transverse wave. A standing wave can be defined as a wave that remains ideal ( constant position). A longitudinal wave is parallel to the direction of propagation. A transverse wave can be defined as a wave where the flow of particles in a medium is directly perpendicular to a direction of propagation of the wave.
When there is a formation of sound waves in a tube the motion is ungoverned. That is at the antinode (open node) there will be a maximum displacement of air. At the node ( close node) there will no displacement of air as it is blocked. The distance from a closed end to the open end is equal to one-fourth of the wavelength of that of a total wavelength of the tube.