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Experimentelle Untersuchung der thermischen Konvektion in einem geneigten Spalt

Experimental investigation of thermal convection in an inclined gap

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Zusammenfassung

Das Verhalten einer Flüssigkeitsströmung in einem engen vertikalen Spalt mit einer gekühlten und einer beheizten Seitenwand wurde experimentell in einer vergangenen Studie hinsichtlich des Wärme- und Massentransports untersucht (Heiland et al. in Heat Mass Transf 43:863–870, 2007). Dieser Studie folgend wurde unter Anwendung der Flüssigkristalltechnik zur Strömungssichtbarmachung eine Untersuchung der thermischen Konvektion in einer engen Kavität unter variablem Neigungswinkel durchgeführt. Geschwindigkeits- und Temperaturfeld der Strömung wurden vermessen. Unter anderem zeigen die Ergebnisse, dass ab einem Neigungswinkel von ca. 5–15 eine drastische Änderung der Strömungs- und Temperaturfeldtopologie auftritt, welche sich qualitativ bis zu einem Neigungswinkel von 90 nicht mehr ändert.

Abstract

The liquid flow behaviour in a small vertical gap with a heated and a cooled sidewall was studied experimentally in a former work as far as heat and mass transfer are concerned (Heiland et al. in Heat Mass Transf 43:863–870, 2007). Following this, a study of thermal convection in a narrow cavity with variable inclination angle has been performed with a liquid crystal tracer technique for flow visualization. Velocity and temperature fields of the flow have been measured. Amongst other things the results show that from an inclination angle of approximately 5–15 on a drastic change of the velocity and temperature field topology occurs, which qualitatively will not change any more when further increasing the inclination angle up to 90.

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Abbreviations

a :

Temperaturleitfähigkeit

b :

Spaltbreite

d :

Tiefe

h :

Höhe

H:

Hue-Wert

Pr:

Prandtl-Zahl

Ra:

Rayleigh-Zahl

T :

Temperatur

T c :

Temperatur der kalten Berandung

T h :

Temperatur der warmen Berandung

ΔT :

Temperaturdifferenz

v :

Geschwindigkeit

x,y :

Kartesische Koordinaten

β :

Thermischer Expansionskoeffizient

γ :

Neigungswinkel

η :

Dynamische Viskosität

ρ :

Fluiddichte

ν :

Kinematische Viskosität

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Correspondence to G. Wozniak.

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Heiland, H.G., Sommer, O. & Wozniak, G. Experimentelle Untersuchung der thermischen Konvektion in einem geneigten Spalt. Forsch Ingenieurwes 76, 87–95 (2012). https://doi.org/10.1007/s10010-012-0157-8

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  • DOI: https://doi.org/10.1007/s10010-012-0157-8

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