Modeling the Voltage Produced by Ultrasound in Seawater by Stochastic and Artificial Intelligence Methods

Abstract

Experiments have proved that an electrical signal appears in the ultrasonic cavitation field; its properties are influenced by the ultrasound frequency, the liquid type, and liquid characteristics such as density, viscosity, and surface tension. Still, the features of the signals are not entirely known. Therefore, we present the results on modeling the voltage collected in seawater, in ultrasound cavitation produced by a 20 kHz frequency generator, working at 80 W. Comparisons of the Box–Jenkins approaches, with artificial intelligence methods (GRNN) and hybrid (Wavelet-ARIMA and Wavelet-ANN) are provided, using different goodness of fit indicators. It is shown that the last approach gave the best model.

Artificial Intelligence Models for the Mass Loss of Copper-Based Alloys under Cavitation

“…Its main parts are as follows [ 3 , 39 ]: The tank (1) containing the liquid subject to the ultrasound cavitation; The high-frequency ultrasound generator (8), designed to work at 220 V, 18 kHz, and three power levels; The piezoceramic transducer (7) that produces cavitation entering into oscillation as a response to the high-frequency signal received from the generator; The control panel (command block) (12) from where the ultrasound generator’s working power is selected; The cooler (11) that is used to maintain a constant temperature of the liquid; The measurement electrodes (13), which are utilized only in the experiments related to capturing the signal induced in the cavitation field; The acquisition data unit (14), used only in the experiments related to electrical signals induced by ultrasound cavitation to collect the signals. …”

“…An ultrasound signal passing through a liquid gives birth to cavitation, a phenomenon defined by the cyclic apparition, increase, and collapse of the bubbles of vapors formed in the liquid [ 1 ]. During these cycles, a voltage is induced near the cavitation zone’s boundaries [ 2 , 3 , 4 ]. Cavitation is an exogenous process accompanied by discontinuities in the liquid’s state, which appear when the pressure drops under critical limits [ 5 ].…”

Fractal Characterization of Brass Corrosion in Cavitation Field in Seawater

“…The experimental plant built for studying the corrosion-erosion in ultrasound cavitation is presented in Figure 1. The principal components are [5,6]:…”

“…Finally, the fractal and multifractal analyses of the absolute mass loss curve and the corroded surface were performed, as described in the next section. The principal components are [5,6]:…”

“…It is accompanied by discontinuities in the liquid's state (as a result of the pressure decrease under critical limits) [2] and high temperatures at the time of the bubbles' collapse. Other consequences of cavitation are vibrations, noise, sonoluminescence, emulsification, unpassivation, corrosion of the materials immersed in the liquid, and the apparition of an electrical signal at the boundary of the cavitation region [3][4][5][6].…”