Effects Of Flow And Non Newtonian Fluids On Nonspherical Cavitation Bubbles

Effects of Flow and Non-Newtonian Fluids on Nonspherical Cavitation Bubbles

Cavitation in Non-Newtonian Fluids

Non-Newtonian properties on bubble dynamics and cavitation are fundamentally different from those of Newtonian fluids. The most significant effect arises from the dramatic increase in viscosity of polymer solutions in an extensional flow, such as that generated about a spherical bubble during its growth or collapse phase. In addition, many biological fluids, such as blood, synovial fluid, and saliva, have non-Newtonian properties and can display significant viscoelastic behaviour. This monograph elucidates general aspects of bubble dynamics and cavitation in non-Newtonian fluids and applies them to the fields of biomedicine and bioengineering. In addition it presents many examples from the process industries. The field is strongly interdisciplinary and the numerous disciplines involve have and will continue to overlook and reinvent each others’ work. This book helps researchers to think intuitively about the diverse physics of these systems, to attempt to bridge the various communities involved, and to convey the interest, elegance, and variety of physical phenomena that manifest themselves on the micrometer and microsecond scales.

The Effects of Flow and Non-Newtonian Fluids on Nonspherical Cavitation Bubbles

Flow cavitation is substantially altered, both at inception and during subsequent dynamics, by the addition of small amounts of water-soluble polymer. Theoretical and experimental single-bubble systems developed here trace the shape of a bubble as it is influenced by a volume change of the cavity, the rheology of the surrounding fluid, the presence of a solid wall, and/or an imposed external flow. The theoretical formulation pertains to a bubble in a fluid which is infinite in extent and contains no barriers or interfaces apart from the bubble surface. An external flow can be imposed, imparting a stress history. In addition, a spherical bubble profile, obtained from present experiments or theories, dictates a volume change and drives the non-sphericities. (Author).