Mohammad Taeibi-Rahni

arXiv2003

Effects of Bulk Viscosity in Non-linear Bubble Dynamics

The non-linear bubble dynamics equations in a compressible liquid have been modified considering the effects of compressibility of both the liquid and the gas at the bubble interface. A new bubble boundary equation has been derived, which includes a new term resulted from the liquid bulk viscosity effects. The influence of this term has been numerically investigated considering the effects of water vapor and chemical reactions on the bubble evolution. The results clearly indicate that the new term has an important damping role at the collapse, so that its consideration decreases the amplitude of the bubble rebounds after the collapse. This damping feature is more remarkable for higher deriving pressures.

physics.flu-dyn↗

arXiv2003

Compressibility Consideration in the Boundary of a Strongly Collapsing Bubble

Equations of radial motion of a gas bubble in a compressible viscous liquid have been modified to account for compressibility at the bubble boundary. A new bubble boundary equation has been derived, including a new term resulted from liquid compressibility. The influence of this term has been numerically investigated using isothermal-adiabatic model for the gas inside the bubble. The results clearly indicate that, at the end of the collapse, the new term has a very significant role and its consideration dramatically changes the bubble characteristics. Moreover, the more intense the collapse is, the more significant the effect of the new term is. Also, it has been reasoned out that, the influence of the new term will be established even when the effects of mass (water vapor) exchange, chemical reactions, and gas dynamics inside the bubble are taken into account.

physics.flu-dyn↗