Wf-3 Helmholtz Resonators
Published: Wednesday 15 March 2006 - Updated: Thursday 31 March 2011
Aim
To demonstrate a Helmholtz resonator, i.e. an acoustic device that exhibits mechanical resonance with small damping.
Apparatus
- Helmholtz Resonators
- Stand
- Tuning Fork or Loudspeaker
- Amplifier
- C.R.O.
Diagrams
Click on pictures to enlarge.
Description
A Helmholtz resonator consists of a volume V fitted with a short open neck N. The air in the neck functions like a piston and the air in the cavity as a spring.
The frequency f, of the free vibrations of the air in the neck is given by
N = (c / 2 Pi) * SQRT (S/lv)