Chaotic behavior of a single spherical gas bubble surrounded by a Giesekus liquid: A numerical study

In the present work, nonlinear oscillations of a spherical, acoustically driven gas bubble in a Giesekus liquid are examined numerically. A novel approach based on the Gauss–Laguerre quadrature (GLQ) method is implemented to solve the integro-differential equation governing bubble dynamics in a Giesekus liquid. It is shown that, using this robust method, numerical results could be obtained at very high amplitudes and frequencies typical of ultrasound applications. The GLQ method also enabled obtaining results at very high Deborah and Reynolds numbers over prolonged dimensionless times not reported previously. Based on the results obtained in this work, it is concluded that the GLQ method is well suited for bubble dynamics studies in viscoelastic liquids. It is also concluded that the extensional-flow behavior of the liquid surrounding the bubble (as represented by the mobility factor in the Giesekus model) has a strong effect on the chaotic behavior of the bubble, and this is particularly so at high Deborah numbers, high amplitudes and/or high frequencies of the acoustic field. A period-doubling bifurcation structure is predicted to occur for certain values of the mobility factor.