Modelling film flows down a fibre

Ruyer-Quil, Christian; Treveleyan, P.; Giorgiutti-Dauphiné, F.; Duprat, Camille; Kalliadasis, Serafim

doi:10.1017/s0022112008001225

Cited by 114 publications

(168 citation statements)

References 26 publications

(56 reference statements)

Supporting

Mentioning

157

Contrasting

Order By: Relevance

“…Therefore, they are only valid for small Reynolds numbers of Re ∼ O (1). Ruyer-Quil et al [14] formulated a two-equation model for the film thickness h and flow rate q using a weighted residuals approach. This model, accounting for inertia and streamwise viscous diffusion, is valid for moderate Reynolds numbers, both small and O(1) aspect ratios of h/a.…”

Section: Introductionmentioning

confidence: 99%

Stability of viscous film flow coating the interior of a vertical tube with a porous wall

Liu

Ding

2017

Phys. Rev. E

View full text Add to dashboard Cite

This is the final published version of the article (version of record). It first appeared online via APS Physics at https://doi.org/10.1103/PhysRevE.95.053101 . Please refer to any applicable terms of use of the publisher. University of Bristol -Explore Bristol Research General rightsThis document is made available in accordance with publisher policies. Please cite only the published version using the reference above. Full terms of use are available: http://www.bristol.ac.uk/pure/about/ebr-terms PHYSICAL REVIEW E 95, 053101 (2017) The stability of the gravity-driven flow of a viscous film coating the inside of a tube with a porous wall is studied theoretically. We used Darcy's law to describe the motion of fluids in a porous medium. The Beaver-Joseph condition is used to describe the discontinuity of velocity at the porous-fluid interface. We derived an evolution equation for the film thickness using a long-wave approximation. The effect of velocity slip at the porous wall is identified by a parameter β. We examine the effect of β on the temporal stability, the absolute-convective instability (AI-CI), and the nonlinear evolution of the interface deformation. The results of the temporal stability reveal that the effect of velocity slip at the porous wall is destabilizing. The parameter β plays an important role in determining the AI-CI behavior and the nonlinear evolution of the interface. The presence of the porous wall promotes the absolute instability and the formation of the plug in the tube. Stability of viscous film flow coating the interior of a vertical tube with a porous wall

show abstract

Section: Introductionmentioning

confidence: 99%

Stability of viscous film flow coating the interior of a vertical tube with a porous wall

Liu

Ding

2017

Phys. Rev. E

View full text Add to dashboard Cite

show abstract

“…These solitary waves have a dominant elevation with a long tail and steep front, typically with capillary ripples preceding the main wave hump. The γ 1 and γ 2 waves are also observed in falling films in the presence of various complexities, such as Marangoni effects due to heating, localized or uniform [22][23][24][25][26], chemical reactions [27][28][29], surfactants [30] and substrate curvature [31][32][33][34][35].…”

Section: Introductionmentioning

confidence: 99%

Self-similarity of solitary waves on inertia-dominated falling liquid films

et al. 2016

View full text Add to dashboard Cite

We propose the first consistent scaling of solitary waves on inertia-dominated falling liquid films, which accurately accounts for the driving physical mechanisms and leads to a self-similar characterization of solitary waves. Direct numerical simulations of the entire two-phase system are conducted using a state-of-the-art finite volume framework for interfacial flows in an open domain that was previously validated against experimental film-flow data with excellent agreement. We present a detailed analysis of the wave shape and the dispersion of solitary waves on 34 different water films with Reynolds numbers Re = 20 − 120 and surface tension coefficients σ = 0.0512 − 0.072 N m −1 on substrates with inclination angles β = 19 • − 90 • . Following a detailed analysis of these cases we formulate a consistent characterization of the shape and dispersion of solitary waves, based on a newly proposed scaling derived from the Nusselt flat film solution, that unveils a self-similarity as well as the driving mechanism of solitary waves on gravity-driven liquid films. Our results demonstrate that the shape of solitary waves, i.e. height and asymmetry of the wave, is predominantly influenced by the balance of inertia and surface tension. Furthermore, we find that the dispersion of solitary waves on the inertia-dominated falling liquid films considered in this study is governed by non-linear effects and only driven by inertia, with surface tension and gravity having a negligible influence.

show abstract

“…i.e. wall curvature effects (Ruyer-Quil et al 2008;, thermocapillary Marangoni effects (Trevelyan & Kalliadasis 2004a,b;Ruyer-Quil et al 2005;Trevelyan et al 2007) and solutal Marangoni effect (Pereira & Kalliadasis 2008). Although it is known that generally WIBL models perform significantly better than Benney-type long-wave models and are valid up to moderate values of the Reynolds number, to truly analyse the range of validity of such long-wave models in any particular setup, it is important to compare their predictions with e.g.…”

Section: Introductionmentioning

confidence: 99%

Absolute and convective instabilities in counter-current gas–liquid film flows

2014

View full text Add to dashboard Cite

Absolute and convective instabilities in counter-current gas-liquid film flows. Mechanics, 763, Additional Information: Journal of Fluid• This is the accepted manuscript of an article subsequently published in We consider a thin liquid film flowing down an inclined plate in the presence of a countercurrent turbulent gas. By making appropriate assumptions, Tseluiko & Kalliadasis (2011) developed low-dimensional non-local models for the liquid problem, namely a long-wave model and a weighted integral-boundary-layer model, that incorporate the effect of the turbulent gas. By utilising these models, along with the Orr-Sommerfeld problem formulated using the full governing equations for the liquid phase and associated boundary conditions, we explore the linear stability of the gas-liquid system. In addition, we devise a generalised methodology to investigate absolute and convective instabilities in the nonlocal equations describing the gas-liquid flow. We observe that at low gas flow rates, the system is convectively unstable with the localised disturbances being convected downwards. As the gas flow rate is increased, the instability becomes absolute and localised disturbances spread across the whole domain. As the gas flow rate is further increased, the system again becomes convectively unstable with the localised disturbances propagating upwards. We find that the upper limit of the absolute instability region is close to the 'flooding' point associated with the appearance of large-amplitude standing waves, as obtained in Tseluiko & Kalliadasis (2011), and our analysis can therefore be used to predict the onset of flooding. We also find that an increase in the angle of inclination of the channel requires an increased gas flow rate for the onset of absolute instability. We generally find good agreement between the results obtained using the full equations and the reduced models. Moreover, we find that the weighted integral-boundary-layer model generally provides better agreement with the results for the full equations than the longwave model. Such an analysis is important for understanding the ranges of validity of the reduced model equations. In addition, a comparison of our theoretical predictions with the experiments of Zapke & Kröger (2000a) shows a fairly good agreement. We supplement our stability analysis with time-dependent computations of the linearised weighted integral-boundary-layer model. To provide some insight into the mechanisms of instability, we perform an energy budget analysis.

show abstract

Modelling film flows down a fibre

Cited by 114 publications

References 26 publications

Stability of viscous film flow coating the interior of a vertical tube with a porous wall

Stability of viscous film flow coating the interior of a vertical tube with a porous wall

Self-similarity of solitary waves on inertia-dominated falling liquid films

Absolute and convective instabilities in counter-current gas–liquid film flows

Contact Info

Product

Resources

About