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

• We study the dynamics of a gas bubble in a non-Newtonian fluid with magnetic field.
• The dynamic impacts of the radial response of the bubble before and after applying the magnetic field are discussed.
• Numerical simulations reveal a series of transitional regimes under the influence of a magnetic field for controlling the nonlinear oscillations of a gas bubble in a nonlinear viscoelastic media, which may lead to bubble collapse.
• This recent model can play an important role in the medical applications such as drug, protein or gene delivery and blood research.

Dynamics 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.