ASA 130th Meeting - St. Louis, MO - 1995 Nov 27 .. Dec 01

5aPAb17. Sound energy loss during sonolysis.

Dmitry A. Selivanovsky

Inst. of Appl. Phys., 46 Ulyanov St., Nizhny Novgorod 603600, Russia

Grigory A. Domrachev

Inst. of Metalloorganic Chemistry, Nizhny Novgorod 603600, Russia

This paper gives an analysis of sound energy losses due to sonolysis --- dissociation of the part of water molecules to radicals H(centered dot) and (centered dot)OH. The value of the energy loss can be evaluated by using the concentration of hydrogen peroxide which appears in the water as a result of cross-recombination of radicals (centered dot)OH+(centered dot)OH=H[inf 2]O[inf 2]. Data previously obtained by different authors were used for the present analysis. Data for fresh water and also for water with dissolved gases were considered. Data covered a sound frequency range from 1.5 kHz to 2 MHz and sound pressure amplitudes 0.6--2.5 atm for normal static pressure and a water temperature of 20 (degrees)C. It is shown that the rate of increasing hydrogen peroxide concentration is proportional to the intensity of sound. The rate is also proportional to the concentration of dissolved oxygen and argon in water while other gases (hydrogen, helium, nitrogen) do not influence the sonolysis rate compared to the degassed water. All the data demonstrate that the energy loss is about proportional to the square of sound frequency, that is, the same frequency dependence with Rayleigh viscous attenuation of sound. The relative values of energy losses are from 10[sup -4] to 10[sup -8] of the Rayleigh sound decay. This value depends on the kind and concentration of dissolved gas in water.

All posters will be on display from 9:00 a.m. to 12:00 noon. To allow contributors an opportunity to see other posters, contributors of odd-numbered papers will be at their posters from 9:00 a.m. to 10:30 a.m. and contributors of even-numbered papers will be at their posters from 10:30 a.m. to 12:00 noon. To allow for extended viewing time, posters will remain on display until 5:00 p.m.