### Strutt Help

Wavenumber
^{1/1, 1/3}
**Strutt|Fundamentals|Angular Wavenumber** inserts the wavenumber of a sound wave in air into each octave band or 1/3-octave band of the selected row.

The wavenumber (`k`) is calculated in (radians per unit length) as:

`k=(2pi)/lambda`, where

`lambda = c//f` is the wavelength of the sound wave

`c` is the wave velocity, temperature dependent (343 m/s at 20 °C)

`f` is the frequency of wave (Hz)

The user may calculate the wave velocity as a function of temperature (using the Speed of Sound calculation) or else use the default value of 343 m/s.

Comments or suggestions to
strutt@arup.com