Hydrodynamics of three-dimensional waves in laminar falling films

Adomeit, Philipp; Renz, Ulrich

doi:10.1016/s0301-9322(99)00079-8

Cited by 139 publications

(85 citation statements)

References 25 publications

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“…Note that the velocity profile is parabolic in the tail and underneath the crest of the solitary wave, even for the case with the highest Reynolds number (case C6, Re = 77). This agrees with previously reported numerical results (Malamataris et al 2002;Gao et al 2003;Malamataris & Balakotaiah 2008) and experimental measurements (Adomeit & Renz 2000;Moran et al 2002;Charogiannis et al 2015). Interestingly, the self-similarity of the velocity profile in the laboratory frame of reference is unaffected by the onset of a recirculation region in the moving frame when the maximum flow velocity exceeds the wave speed (for instance, in case C6).…”

Section: Comparison Of Experimental and Numerical Resultssupporting

confidence: 92%

“…Particle-image velocimetry (PIV) and particle tracking velocimetry (PTV), instead, allow for 2D as well as 3D velocity-field characterisation by tracking the motion of seeded particle groups (PIV) or individual particles (PTV). Examples of the use of micro-PIV include the study of laminar, vertically falling films (Adomeit & Renz 2000) and the capillary-wave region (Dietze et al 2008), while PIV/PTV has been used, for example, in the study of downward co-current gas-liquid annular flows (Zadrazil, Matar & Markides 2014b), where the presence of multiple recirculation zones within the disturbance waves was revealed.…”

Section: F Denner and Othersmentioning

confidence: 99%

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Solitary waves on falling liquid films in the inertia-dominated regime

et al. 2018

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We offer new insights and results on the hydrodynamics of solitary waves on inertiadominated falling liquid films using a combination of experimental measurements, direct numerical simulations (DNS) and low-dimensional (LD) modelling. The DNS are shown to be in very good agreement with experimental measurements in terms of the main wave characteristics and velocity profiles over the entire range of investigated Reynolds numbers. And, surprisingly, the LD model is found to predict accurately the film height even for inertia-dominated films with high Reynolds numbers. Based on a detailed analysis of the flow field within the liquid film, the hydrodynamic mechanism responsible for a constant, or even reducing, maximum film height when the Reynolds number increases above a critical value is identified, and reasons why no flow reversal is observed underneath the wave trough above a critical Reynolds number are proposed. The saturation of the maximum film height is shown to be linked to a reduced effective inertia acting on the solitary waves as a result of flow recirculation in the main wave hump and in the moving frame of reference. Nevertheless, the velocity profile at the crest of the solitary waves remains parabolic and self-similar even after the onset of flow recirculation. The upper limit of the Reynolds number with respect to flow reversal is primarily the result of steeper solitary waves at high Reynolds numbers, which leads to larger streamwise pressure gradients that counter flow reversal. Our results should be of interest in the optimisation of the heat and mass transport characteristics of falling liquid films and can also serve as a benchmark for future model development.

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Section: Comparison Of Experimental and Numerical Resultssupporting

confidence: 92%

Section: F Denner and Othersmentioning

confidence: 99%

Solitary waves on falling liquid films in the inertia-dominated regime

et al. 2018

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“…При этом авторы ограничиваются измерением на разных расстояниях y от поверхности, по которой происходит течение, продольной компоненты скорости V x , направленной вдоль основного течения, как, например, в работе [4], где для измерений использовался фотохроматический метод. В [5,6] для измерения скорости жидкости в волновых пленках применялся современный полевой метод цифровой трассерной визуализации (ЦТВ), являющийся на данный момент наиболее эффективной техникой опти-ческой диагностики потоков. Однако, как и в работе [4], результаты ограничивались измерением V x (y).…”

Section: поступило в редакцию 3 мая 2017 гunclassified

Структура Течения В Трехмерных Волнах На Вертикально Стекающей Пленке Жидкости

Квон¹,

Бобылев²,

Гузанов³

et al. 2017

Письма В Журнал Технической Физики

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Проведены одновременные измерения полей скорости и толщины пленки в трехмерных волнах, образующихся в результате распада регулярных двумерных волн при пленочном течении жидкости по вертикальной пластине. Построены поля скорости на разном расстоянии от пластины с привязкой к конкретным участкам трехмерной волны. Показано, что поток жидкости в волне имеет сложную структуру с существованием областей возвратного течения и поперечных потоков, при этом основные области этих потоков находятся под главным гребнем волны. DOI: 10.21883/PJTF.2017.18.45027.16851

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“…The disadvantage of the camera is that the detector chip requires a more complicated calibration procedure than a single point pyrometer and thus the pyrometer is better suited if absolute temperature measurements are required. The thickness distribution of three-dimensional waves in laminar falling films was investigated by (Adomeit & Renz, 2000) using a fluorescence technique. A small amount of sodium-fluorescine (C 20 H 10 Na 2 O 5 ) was added to the film as a fluorescent tracer.…”

Section: Thermal-capillary Metastable Structures and Thermal-capillarmentioning

confidence: 99%