The Effect Of Viscosity On Sound Wave Propagation And Bubble Vibration In Liquid With Bubbles

The propagation of acoustic wave irn the liquid with bubble is an important research content in the field of acoustic cavitations.Viscous liquid with bubble,attenuation coefficient,phase velocity,resonance absorption,and cavitations is caused when the intensity of the driving sound field is large enough,so,the research on the propagation of sound waves in liquid with bubble is of great importance both in theory and in practice.In the study of this problem,the following work is done on the linear propagation of sound waves in the liquid with bubble:In the first part,it summarize the theory development status that linear propagation of acoustic wave in liquid with bubble and the bubble dynamic at home and abroad,and it illustrates the interaction theory of bubbles in water.In the second part,the linear small amplitude wave equations that are propagation in the ideal fluid and effective medium are derived.In this case,the liquid with bubbles is considered a uniform and effective medium,using perturbation method and linearization approximation ignoring the second order or above,the acoustic wave equation of acoustic wave in the viscous liquid with bubbles is derived.In the process of derivation,the effect of liquid viscosity on linear acoustic wave propagation is fully taken into account compared,the acoustic wave equation in ideal fluid and effective media is compared,and the influence factors of sound propagation are discussed.In the third part,it focuses on the propagation characteristics of sound waves in the effective medium.The results show that the resonance absorption of acoustic wave is caused by bubble resonance.Because of the interaction between bubbles,the resonance absorption frequency of acoustic waves is not the same as the resonance frequency of bubbles.The half width of the resonance absorption frequency is also increased.In the low-frequency non-resonant region,by investigating the influence of liquid viscosity,surface tension coefficient and bubble content on sound propagation founding that,the acoustic attenuation coefficient has the same dependence on liquid viscosity as well as the liquid surface tension coefficient.it increases linearly with the increasing of viscosity and surface tension coefficient,but both have little effect on the speed of sound,it's almost negligible,the presence of bubbles changes the propagation parameters of sound waves,the increase of bubble content increases the acoustic attenuation coefficient,the speed of sound decreases.In addition,there are two ways that the effect of viscosity on sound waves,one is to exert influence through the bubble oscillation equation;the second is to exert influence through the wave equation of sound waves.Then the role of viscosity in these two methods was studied and analyzed,the conditions of approximate establishment that some approximate theories are given.In the fourth part,taking into account the interaction between bubbles and the effect of liquid viscosity on the vibration of bubbles,assuming the liquid is incompressible,focusing on the nonlinear vibration of a single bubble when the sound waves are propagating through the liquid with bubbles.Studies show that,to a certain extent,the liquid viscosity inhibits the process of cavitations,the greater the viscosity of liquid,the more difficult it is to cavitations,when the viscosity of the liquid reaches a certain degree,the bubbles will do periodic small amplitude vibration near the equilibrium position.when the volume content of the bubbles is smaller,the vibration of the individual bubbles in liquid with bubbles is the same as of the individual bubble in the ideal fluid,when the volume content of the bubbles is larger,different bubble content can lead to different vibration processes.It's a good match for the relevant textbook.In this paper,under the certain condition of approximation,the theoretical and experimental study on the propagation characteristics of linear sound waves in sticky liquid containing bubbles,we found the specific effects of liquid viscosity on sound propagation and bubble oscillation,and it has further instruction in the develop of sound propagation theory.