Effect of magnetic field on the radial pulsations of a gas bubble in a non-Newtonian fluid

Abstract

a b s t r a c tDynamics of acoustically driven bubbles' radial oscillations in viscoelastic fluids are known as complex and uncontrollable phenomenon indicative of highly active nonlinear as well as chaotic behavior. In the present paper, the effect of magnetic fields on the non-linear behavior of bubble growth under the excitation of an acoustic pressure pulse in non-Newtonian fluid domain has been investigated. The constitutive equation [Upper-Convective Maxwell (UCM)] was used for modeling the rheological behaviors of the fluid. Due to the importance of the bubble in the medical applications such as drug, protein or gene delivery, blood is assumed to be the reference fluid. It was found that the magnetic field parameter (B) can be used for controlling the nonlinear radial oscillations of a spherical, acoustically forced gas bubble in nonlinear viscoelastic media. The relevance and importance of this control method to biomedical ultrasound applications were highlighted. We have studied the dynamic behavior of the radial response of the bubble before and after applying the magnetic field using Lyapunov exponent spectra, bifurcation diagrams and time series. A period-doubling bifurcation structure was predicted to occur for certain values of the parameters effects. Results indicated its strong impact on reducing the chaotic radial oscillations to regular ones.

Dynamics of magnetic microbubble transport in blood vessels

“…Our observations indicate that the magnitude of shear stress near the vessel wall was increased under applied external fields. In contrast, a uniform magnetic field is verified to weaken the oscillating gas bubble without coated magnetic particles, and is supported by inhibition of sonoluminescence [52][53][54] and reduction of the blood-brain barrier opening volume. [55] These facts could serve as contrary evidence to approve the model in this work; fiercer pulsation of MMBs is achieved by combined acoustic and magnetic fields.…”

Numerical study on a polymer-shelled microbubble submerged in soft tissue

“…Lauterborn and his colleagues [43][44][45] have made great contributions by introducing the method of chaos physics to a model of a driven spherical gas bubble in water to determine its dynamic properties, especially its resonance behavior and bifurcation structure. Also, based on the previous works, the chaotic behavior of free bubbles observed both theoretically and experimentally [46][47][48][49][50], but this is not investigated for the case of UCAs, and it will be helpful to survey from this point of view because the method of chaos physics provides extensive knowledge about rich nonlinear dynamical systems. Moreover, neglecting liquid compressibility is not suitable for high-pressure amplitudes where the wall velocity of the agent is equal to the speed of sound in liquid [31], so the effects of liquid compressibility on the microbubble dynamics should be considered [40,41].…”

Study of encapsulated microbubble cluster based on association schemes perspective

“…On the other hand, UCAs (single or cluster) undergo complex dynamic behaviors while they are exposed to an ultrasound field, which depending on the applied acoustic amplitudes, they will respond linear [28,29] or nonlinear pulsations [26,30,31,32,33,34]. The nonlinear nature of the equations needs specialized tools for analyzing due to the fact that linear and analytical solutions are inadequate.…”