Open AccessCALCULATION OF A SONOCAPILLARY EFFECT DEPENDENCE ON AN ULTRASONIC FREQUENCY BASED ON A THRESHOLD CAVITATION CRITERION
Author(s) -
Н.В. Михайлова,
Ivan Smirnov,
Aliya Sharipova,
Viacheslav Slesarenko
Publication year - 2020
Publication title -
problemy pročnosti i plastičnosti
Language(s) - English
Resource type - Journals
ISSN - 1814-9146
DOI - 10.32326/1814-9146-2020-82-1-64-74
Subject(s) - cavitation , capillary action , ultrasonic sensor , vibration , mechanics , oscillation (cell signaling) , acoustics , materials science , sonochemistry , amplitude , bubble , sound pressure , chemistry , physics , optics , composite material , biochemistry
The possibility of calculating parameters of the ultrasonic capillary effect depending on frequency of acoustic vibrations in liquid is considered. According to known experimental data, the intensification of fluid motion in the capillary is mainly associated with the formation and collapse of cavitation bubbles at the capillary end. Therefore, it is assumed that the ultrasonic capillary effect occurs as a result of cavitation processes at the entrance to the capillary channel, while cavitation processes depend on the frequency of ultrasonic vibrations. The threshold pressure at cavitation, leading to the rise of fluid, for a given ultrasound frequency is determined by the criterion of incubation time of cavitation. The size and number of cavitation bubbles at the considered threshold pressure depend on ultrasound frequency. The number of bubbles in the cavitation area is determined by solving the problem of packing equal circles in a larger circle, taking into account the distance the influence of the bubbles on each other. The height of the liquid rise is calculated based on the assumption that during one cycle of oscillation of the cavitation region, the sound capillary pressure performs the work on lifting the liquid column to a certain height due to the energy of collapsed bubbles. This approach makes it possible to determine the threshold amplitude of acoustic vibrations and evaluate the corresponding behaviour of sound-capillary pressure in the frequency range of 7-62 kHz. The specified range is determined by the frequency requirements for the ratio of the size of the cavitation process zone and the capillary diameter. Thus, the obtained model of the ultrasonic capillary effect takes into account the diameter of the capillary and allows to determine the frequency range over which this effect can be realized. The calculation results show good agreement with the known experimental data in water. The results of calculations using the model showed that the highest sound capillary pressure is reached in the range of 10-20 kHz.