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Effect of Longitudinal Minigrooves on Flow Stability and Wave Characteristics of Falling Liquid Films

Helbig, K. ; Nasarek, R. ; Gambaryan-Roisman, Tatiana ; Stephan, Peter (2009)
Effect of Longitudinal Minigrooves on Flow Stability and Wave Characteristics of Falling Liquid Films.
In: Journal of Heat Transfer, 131 (1)
Artikel, Bibliographie

Kurzbeschreibung (Abstract)

Falling liquid films are used in many industrial apparatuses. In many cases the film flow along a wall with topography is considered advantageous for intensification of the heat and mass transport. One of the promising types of the wall topography for the heat transfer intensification is comprised of minigrooves aligned along the main flow direction. The wall topography affects the development of wavy patterns on the liquid-gas interface. Linear stability analysis of the falling film flow based on the long-wave theory predicts that longitudinal grooves lead to the decrease in the disturbance growth rate and therefore stabilize the film. The linear stability analysis also predicts that the frequency of the fastest growing disturbance mode and the wave propagation velocity decrease on a wall with longitudinal minigrooves in comparison with a smooth wall. In the present work the effect of the longitudinal minigrooves on the falling film flow is studied experimentally. We use the shadow method and the confocal chromatic sensoring technique to study the wavy structure of falling films on smooth walls and on walls with longitudinal minigrooves. The measured film thickness profiles are used to quantify the effect of the wall topography on wave characteristics. The experimental results confirm the theoretical predictions.

Typ des Eintrags: Artikel
Erschienen: 2009
Autor(en): Helbig, K. ; Nasarek, R. ; Gambaryan-Roisman, Tatiana ; Stephan, Peter
Art des Eintrags: Bibliographie
Titel: Effect of Longitudinal Minigrooves on Flow Stability and Wave Characteristics of Falling Liquid Films
Sprache: Englisch
Publikationsjahr: 2009
Titel der Zeitschrift, Zeitung oder Schriftenreihe: Journal of Heat Transfer
Jahrgang/Volume einer Zeitschrift: 131
(Heft-)Nummer: 1
URL / URN: http://dx.doi.org/10.1115/1.2993539
Kurzbeschreibung (Abstract):

Falling liquid films are used in many industrial apparatuses. In many cases the film flow along a wall with topography is considered advantageous for intensification of the heat and mass transport. One of the promising types of the wall topography for the heat transfer intensification is comprised of minigrooves aligned along the main flow direction. The wall topography affects the development of wavy patterns on the liquid-gas interface. Linear stability analysis of the falling film flow based on the long-wave theory predicts that longitudinal grooves lead to the decrease in the disturbance growth rate and therefore stabilize the film. The linear stability analysis also predicts that the frequency of the fastest growing disturbance mode and the wave propagation velocity decrease on a wall with longitudinal minigrooves in comparison with a smooth wall. In the present work the effect of the longitudinal minigrooves on the falling film flow is studied experimentally. We use the shadow method and the confocal chromatic sensoring technique to study the wavy structure of falling films on smooth walls and on walls with longitudinal minigrooves. The measured film thickness profiles are used to quantify the effect of the wall topography on wave characteristics. The experimental results confirm the theoretical predictions.

Fachbereich(e)/-gebiet(e): 16 Fachbereich Maschinenbau
16 Fachbereich Maschinenbau > Fachgebiet für Technische Thermodynamik (TTD)
Exzellenzinitiative
Exzellenzinitiative > Exzellenzcluster
Zentrale Einrichtungen
Exzellenzinitiative > Exzellenzcluster > Center of Smart Interfaces (CSI)
Hinterlegungsdatum: 17 Mär 2015 15:08
Letzte Änderung: 08 Aug 2019 13:30
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