Liquid velocity fluctuations and energy spectra in three-dimensional buoyancy driven bubbly flows

Abstract

We present a direct numerical simulation (DNS) study of pseudo-turbulence in buoyancy driven bubbly flows for a range of Reynolds ($\Rey$) and Atwood ($\At$) numbers. We study the probability distribution function of the horizontal and vertical liquid velocity fluctuations and find them to be in quantitative agreement with the experiments. The energy spectrum shows the $k^{-3}$ scaling at high $\Rey$ and becomes steeper on reducing the $\Rey$. To investigate the spectral transfers in the flow, we derive the scale-by-scale energy budget equation. Our analysis shows that, for scales smaller than the bubble diameter, the net production because of the surface tension and the kinetic energy flux balances viscous dissipation to give the $k^{-3}$ scaling of the energy spectrum for both low and high $\At$.

arXiv admin note: text overlap with arXiv:1809.04759

References in corpus (4)

• Bubbly and Buoyant Particle-Laden Turbulent Flows
• Experimental investigation of the turbulence induced by a bubble swarm rising within an incident turbulence
• Direct numerical simulations of statistically steady, homogeneous, isotropic fluid turbulence with polymer additives
• The clustering morphology of freely rising deformable bubbles

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• Numerical study on turbulence modulation of finite-size particles in plane-Couette flow
• Scale-by-scale kinetic energy budgets in multiphase turbulence
• Elastic Pseudoturbulence in Polymer Solutions
• Scale-by-scale energy transfers in bubbly flows
• Coagulation drives turbulence in binary fluid mixtures
• Conversions between kinetic and surface energy in periodically forced multiphase turbulence