Inverse Energy Cascade Structure of Turbulence in a Bubbly Flow. Numerical Analysis Using Eulerian-Lagrangian Model Equations.

Murai, Yuichi; Kitagawa, Atsuhide; Song, Xiang-qun; Ohta, Junichi; Yamamoto, Fujio

doi:10.1299/jsmeb.43.197

Cited by 15 publications

(12 citation statements)

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“…We find agreement with the results of [56] on the strongly anisotropic energy distribution along the three velocity components. Indeed, also in that work, about the 90% of the flow energy is contained in the vertical component (z) of the fluid velocity.…”

Section: Evolution In Time For Spectrasupporting

confidence: 90%

“…The time evolution of the energy spectrum can be compared to the one presented by [56], where the authors study a similar system, namely fluid motion generated by rising bubbles, by applying a different technique for the implementation of two-way coupling. The results agree qualitatively, i.e., the initial induction of structures at large scale is followed by a state in which the slope of the energy spectrum is reduced.…”

Section: Evolution In Time For Spectramentioning

confidence: 99%

“…We carry on the comparison with the results of [56], by looking at the high wavenumbers behavior of the spectrum. In that paper a steeper slope with respect to homogeneous and isotropic turbulence is observed.…”

Section: Evolution In Time For Spectramentioning

confidence: 99%

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Evolution of energy in flow driven by rising bubbles

Mazzitelli

Lohse

2009

Phys. Rev. E

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We investigate by direct numerical simulations the flow that rising bubbles cause in an originally quiescent fluid. We employ the Eulerian-Lagrangian method with two-way coupling and periodic boundary conditions. In order to be able to treat up to 288000 bubbles, the following approximations and simplifications had to be introduced, as done before, e.g., by Climent and Magnaudet, Phys. Rev. Lett. 82, 4827 (1999). (i) The bubbles were treated as point particles, thus (ii) disregarding the near-field interactions among them, and (iii) effective force models for the lift and the drag forces were used. In particular, the lift coefficient was assumed to be 1/2, independent of the bubble Reynolds number and the local flow field. The results suggest that large-scale motions are generated, owing to an inverse energy cascade from the small to the large scales. However, as the Taylor-Reynolds number is only in the range of 1, the corresponding scaling of the energy spectrum with an exponent of -5/3 cannot develop over a pronounced range. In the long term, the property of local energy transfer, characteristic of real turbulence, is lost and the input of energy equals the viscous dissipation at all scales. Due to the lack of strong vortices, the bubbles spread rather uniformly in the flow. The mechanism for uniform spreading is as follows. Rising bubbles induce a velocity field behind them that acts on the following bubbles. Owing to the shear, those bubbles experience a lift force, which makes them spread to the left or right, thus preventing the formation of vertical bubble clusters and therefore of efficient forcing. Indeed, when the lift is artificially put to zero in the simulations, the flow is forced much more efficiently and a more pronounced energy that accumulation at large scales (due to the inverse energy cascade) is achieved.

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Section: Evolution In Time For Spectrasupporting

confidence: 90%

Section: Evolution In Time For Spectramentioning

confidence: 99%

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Evolution of energy in flow driven by rising bubbles

Mazzitelli

Lohse

2009

Phys. Rev. E

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“…Many investigators (e.g., Druzhinin and Elghobashi, 1998;Fujiwara et al, 2004;Lakkaraju et al, 2011;Liu et al, 2011;Murai et al, 2000;Nierhaus et al, 2007;Pakhomov and Terekhov, 2016;Pang et al, 2013;Rensen et al, 2005;Roghair et al, 2011b;Tryggvason et al, 2011;Uchiyama and Kusamichi, 2013;Yang et al, 2002) have performed bubbly flow simulations using various multiphase simulation methods (Euler-Lagrange, fronttracking, and Euler-Euler methods) in order to study bubbly flow turbulence. Most simulation studies revolve around turbulent channel or pipe flows with shear-produced turbulence, which shows a different turbulent behavior compared to pseudo-turbulence and BDT found in buoyancy driven flows such as bubble columns.…”

Section: Introductionmentioning

confidence: 99%

Computational study of buoyancy driven turbulence in statistically homogeneous bubbly flows

Panicker

Passalacqua

Fox

2020

Chemical Engineering Science

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“…8, the fluctuation velocity mainly grows on the sides of the bubble plume but the core part of the plume is relatively calm. The region near the top surface is activated by horizontal fluctuations while the side parts of the plume are activated by vertical fluctuations [29,30]. This is explained by the slow oscillation of the bubble plume; that is, when the bubble plume oscillates in the lateral direction, the bubble velocity at a local point inside the bubble plume fluctuates in the vertical direction.…”

Section: Statistical Analysis Of Plane Bubble Plumesmentioning

confidence: 99%