Elastic Pseudoturbulence in Polymer Solutions

Abstract

We study the effects of polymer additives on pseudoturbulence induced by a swarm of bubbles rising in a quiescent fluid. We find that, beyond a critical polymer concentration, the energy spectra of velocity fluctuations in bubble-induced turbulence decay more steeply with respect to the wavenumber $k$. This new scaling is significantly steeper than the classical $k^{-3}$ scaling observed for bubbles in Newtonian fluids; it is independent of the gas volume fraction in the inertial limit and occurs within the length scales between the bubble wake length and the bubble diameter. Furthermore, we provide strong evidence that the presence of polymers enhances the coherence of the flow, highlighting the significant role of polymer additives in modifying the characteristics of pseudoturbulence.

16 pages, 15 figures

References in corpus (22)

• Efficient Mixing at low Reynolds numbers using polymer additives
• Elasto-inertial turbulence
• Precision Measurements of Stretching and Compression in Fluid Mixing
• Bubbly and Buoyant Particle-Laden Turbulent Flows
• Exceeding the asymptotic limit of polymer drag reduction
• On the mechanism of elasto-inertial turbulence
• Bubble drag reduction requires large bubbles
• Energy spectra in turbulent bubbly flows
• Experimental investigation of the turbulence induced by a bubble swarm rising within an incident turbulence
• The evolution of energy in flow driven by rising bubbles
• A first coherent structure in elasto-inertial turbulence
• Experimental investigation of heat transport in homogeneous bubbly flow
• Liquid velocity fluctuations and energy spectra in three-dimensional buoyancy driven bubbly flows
• Elastic wake instabilities in a creeping flow between two obstacles
• Polymer heat transport enhancement in thermal convection: the case of Rayleigh-Taylor turbulence
• An experimental study on the multiscale properties of turbulence in bubble-laden flows
• Hydrodynamic interaction of a bubble pair in viscoelastic shear-thinning fluids
• Role of elasto-inertial turbulence in viscoelastic drag-reducing turbulence
• Lagrangian stretching reveals stress topology in viscoelastic flows
• Viscoelastic Suppression of Gravity-Driven Counterflow Instability
• The emergence of bubble-induced scaling in thermal spectra in turbulence
• Velocity fluctuations for bubbly flows at small Re