Estimation of absolute sound pressure in a small-sized sonochemical reactor

A small-sized sonochemical reactor in which the absolute value of the sound pressure amplitude can be estimated from the vibration velocity of the transducer was investigated. The sound pressure distribution in the reactor and the relationship between the vibration velocity and the sound pressure amplitude were derived through Helmholtz wave equation. The reactor consists of a bolt-clamped Langevin transducer and a rectangular cell with a tungsten reflector. A 3λ/4-standing-wave-field was generated in the reactor to simplify the sound pressure distribution. The sound pressure distribution was measured from the optical refractive index change of water using a laser interferometer. The experimental and theoretical results showed a good agreement in the absolute value of the sound pressure amplitude, and it was confirmed that the sound pressure in the sonochemical reactor can be estimated from the input current of the vibrator.

► We have proposed a small-sized sonochemical reactor.
► The reactor consists of a BLT and a rectangular cell smaller than the wavelength.
► An one-dimensional standing-wave-field of 3/4-wavelength was generated in the reactor.
► The absolute amplitude of the sound pressure can be predicted from the input current.
► The predicted value agreed well with the measurements using an interferometer.