Acoustic frequency for bubble size correlation using acoustic emissions

Abstract

In this study, a correlation between acoustic frequency and the bubble size of a single bubble burst at the free surface has been demonstrated. Bubble burst was used as it is an acoustically noisy process, independent parameter and potential source of AE in a liquid medium. An AE transducer was used to record sound as the bubble bursts at the free surface. The acoustic data were then processed to extract the bursting frequency associated with the bubble size. The frequency of the acoustic bursting has been shown to be related to the size of the bubble. The effects of liquid viscosity on acoustically determined bubble size has also been demonstrated.

Inversion of Volume Scattering Function for Estimation of Bubble Size Distribution in Ocean Waters

“…The number density of bubbles depends on wind speed. Measurements and models in previous studies have confirmed the bubble size distributions typically following a power law distribution with mean slope values (α) ranging from 3.6 to 4.6 [8], [29] and an average mean slope value of 4 [36], [37]. The bubble size distribution is given by ()…”

“…However, accurate prediction of bubble diameters in oceans has been a challenge for the available light-scattering models. More recently, several techniques have been developed to measure or predict the bubble size distribution in water, for example, laser diffraction scattering (LD) [27], static and dynamic light scattering (SLS, DLS), particle tracking analysis (PTA) [28], acoustic sensors [29], video imaging [30], and remote sensing techniques [31]. An inversion method was also developed based on the Critical Angle Refractometry and Sizing technique (CARS) [20], [32]- [33] for the characterization of bubbly flows (size distribution and refractive index of bubbly flow).…”

About Determining the Distribution of Air Bubbles in Water by Sizes Using a Passive Hydroacoustic Method

“…According to [12], the spectrum of sound emitted by bubbles can be used to determine their size. Then this idea was developed in [13][14][15][16][17][18][19]. But all the works do not take into account the fact that the bubbles create noise not only as a result of pulsations, but also when they are separated from the source and collapse.…”

Passive Acoustic Method in Bubble Size Distribution Determination

“…According to work [15], the bubble emitted spectrum could be used to determine its size. Then, this idea found its development in works [16][17][18][19][20].…”