Sound Velocity and Attenuation in Bubbly Mixtures Measured in Standing Wave Tubes

Abstract

Experimental measurements of sound velocity and attenuation constant in a mixture of air bubbles in fresh water, using a standing wave tube, are described. Bubble sizes in the mixtures were controlled between about 0.08- and 0.26-in. diameter, concentrations ranged from 0.03 to 1%, and applied frequencies from 60 to 20 000 cps. Bubbles in each mixture were of a single uniform size except for one series of experiments in which mixtures of bubbles of two discrete sizes were used. Attenuation constants were obtained for each mixture through a range of frequencies, including natural frequencies of the bubbles in the mixture. Velocity measurements were not obtained near the natural frequencies of the bubbles because high attenuation prevented the establishment of standing waves. Data obtained in the tubes were reduced to mean, infinite conditions and compared with available theory. The measurements show that theory gives at least a good estimate of both velocity and attenuation constant in the region investigated.

Wave Velocity Dispersion and Attenuation in Media Exhibiting Internal Oscillations

“…Figures 1 and 8 of Commander and Prosperetti (1989) show the dispersion and phase velocity, respectively, of water containing gas bubbles with only one size (r=9.94x10 -4 m) and a gas volume fraction φ g =3.77x10 -4 . Also, it is shown that the theory of Commander and Prosperetti (1989) matches the experimental data of Silberman (1957) for the same model conditions. Fig.…”

“…All, the low-frequency-limit, the highfrequency-limits and the complicated dispersion behavior in the vicinity of the resonance frequency is almost identical. Also, the data of Silberman (1957) is equally well matched by our model in comparison with the model of Commander and Prosperetti (1989). Attenuation in Commander and Prosperetti (1989) is given in dB/cm, that is, a logarithmic unit with an arbitrary reference value.…”

“…Our model matches the Commander and Prosperetti (1989). Data points are also taken from Commander and Prosperetti (1989), who took the data from Silberman (1957). All values are plotted as absolute values.…”

“…This particular case was studied by a number of researchers (e.g. Minnaert, 1933;Carstensen & Foldy, 1947;Fox et al, 1955;MacPherson, 1957;Silberman, 1957;van Wijngaarden, 1972;Commander & Prosperetti, 1989) and a large number of experimental data is available, as well as detailed theory. However, we choose a different approach for deriving our equations.…”

Ultrasound-based density determination via buffer rod techniques: a review

“…The bubble size governs the resonance frequency of a bubble, and therefore the bubble size distribution with respect to the main frequency defines the degree of attenuation (Carstensen and Foldy, 1947;Silberman, 1957;Fox et al, 1995). According to Eq.…”