Bubble In Viscous Fluid Research Articles

Resonance properties of forced oscillations of particles and gaseous bubbles in a viscous fluid at small Reynolds numbers

We consider small oscillations of micro-particles and gaseous bubbles in a viscous fluid around equilibrium states under the action of a sinusoidal external force. Exact solutions to the governing integro-differential equations containing both Stokes and memory-integral drag forces are obtained. The main aim of this study is to clarify the influence of the memory-integral drag force on the resonance characteristics of oscillating particles or gaseous bubbles in a viscous fluid at small Reynolds numbers. The resonant curves (the amplitude versus the frequency of an external force) and phase-frequency dependences are obtained for both these objects and compared with the corresponding dependences of the traditional oscillator with the Stokes drag force only.

Coalescence and rising behavior of co‐axial and lateral bubbles in viscous fluid: a CFD study

AbstractThe coalescence and rising behavior of co‐axial and lateral bubbles play a valuable role in industrial bubble column which operates at non‐ambient conditions. The volume of fluid with the continuum surface force (VOF‐CSF) model is used for the present study. Three main case studies, namely under ambient and aqueous condition, μ* = σ* = 1, under reduced viscosity, μ* = 0.1, and surface tension, σ* = 0.1, are investigated and compared using two co‐axial bubbles and three lateral bubble rise configuration models. The latter two cases represent operating conditions at above the ambient temperature or pressure. Prior to investigating the main cases, the model is validated with the experimental data from the literature for a single bubble and two lateral bubble coalescence. It is found that reducing viscosity and surface tension has a significant effect on the co‐axial bubbles (or a pair of bubbles rising in a vertical line) and three lateral bubble growth and coalescence characteristics, as compared to ambient condition. © 2017 Curtin University of Technology and John Wiley & Sons, Ltd.

Effect of pressure-oscillation on gas absorption rate from a bubble in viscous fluid

Effect of pressure-oscillation on gas absorption rate from a bubble in viscous fluid

Particle and bubble dynamics in a creeping flow

Dynamics of a solid particle and non-deformable gaseous bubble in viscous fluid are studied analytically and numerically within the framework of creeping flow regime (flow at vanishingly small Reynolds numbers). Equations of motion for the particle and bubble include the consideration of the buoyancy force, Stokes drag force and memory-integral drag force. Exact analytical solutions are obtained and categorised in terms of inclusion (particle or bubble) density with respect to the density of a surrounding fluid. Through the analytical and numerical solutions, the dynamics of solid particle and air bubble in water have been found to behave differently especially at the early stages of motion, whereas some qualitative similarities exist in the long-term asymptotic.

The collapse and rebound of laser-induced cavitation bubble in viscous fluid

The oscillation property of a laser-induced cavitation bubble in a viscous fluid is investigated by a sensitive fiber-optic sensor based on optical beam deflection. The temporal and spatial evolutions of the bubble wall during the expansion and collapse are traced according to sequential waveforms induced by the bubble oscillation. Both the maximum and minimum bubble radii at each oscillation cycle are determined by experiment. Further, in combination with the theoretical analysis and numerical calculation, the variation of the maximum and minimum radii during oscillation and life-time of the bubble in different viscous fluids is obtained. The experimental results indicate that the liquid viscosity has an obvious influence on the bubble oscillation; larger viscosity makes the bubble contract more slowly, and the corresponding minimum radius and the bubble life-time become larger and longer, while the maximum radius is smaller.

Necessary and sufficient conditions for description of the motion of objects in a viscous fluid under ultrasonic actions

Necessary and sufficient conditions are formulated for theories that describe the motion of solid particles and gas bubbles in viscous fluid under the action of acoustic harmonic waves.