Wf-2 Helmholtz Resonators

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.

Helmholtz Resonator Diagram

Helmholtz Resonator Diagram.

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

Helmholtz Equation

Where S is the area of the neck

L is the length of the neck

V is the volume of the cavity