Non-spherical bubble behavior in vortex flow fields

• Published in: Computational mechanics Vol. 32; no. 4-6; pp. 281 - 290
• Main Authors: CHOI, J.-K, CHAHINE, G. L
• Format: Conference Proceeding Journal Article
• Language: English
• Published: Heidelberg Springer 01.12.2003; Berlin Springer Nature B.V
• Subjects: Acoustics; Axisymmetric flow; Boundary element method; Boundary-integral methods; Bubbles; Collapse; Computational fluid dynamics; Computational methods in fluid dynamics; Computational techniques; Computer simulation; Deformation; Exact sciences and technology; Fluid dynamics; Fluid flow; Fundamental areas of phenomenology (including applications); Mathematical analysis; Mathematical methods in physics; Mathematical models; Physics; Potential flow; Underwater sound; Vortices
• ISSN: 0178-7675; 1432-0924
• DOI: 10.1007/s00466-003-0485-5

The boundary element method (BEM) is applied to solve the unsteady behavior of a bubble placed in a vortex flow field. The steady vortex field is given in terms of the viscous core radius and the circulation, both of which may vary along the vortex axis. For this study, 2DynaFS©, an axisymmetric potential flow code which has been verified successfully for diverse type of fluid dynamic problems, is extended. The modifications to accommodate the ambient vortex flow field and to model the extreme deformations of the bubble are presented. Through the numerical simulations, the time history of the bubble geometry and the corresponding pressure signal at a fixed field point are obtained. A special effort is made to continue the numerical simulation after the bubble splits into two or more sub-bubbles. Indeed, it is found that an elongated bubble sometimes splits into smaller bubbles, which then collapse with the emission of strong pressure signals. The behavior of the axial jets after the split is also studied in more detail.