Eintrag in der Universitätsbibliographie der TU Chemnitz
Tadrous, Ebram
Wozniak, Günter (Prof. Dr.-Ing.); Szymczyk, Janusz A. (Prof. Dr.-Ing.)
Experimental investigation of the transition of Marangoni convection around a stationary gas bubble towards turbulent flow
Experimentelle Untersuchung des Übergangs der Marangoni-Konvektion um eine stationäre Gasblase in Richtung turbulenter Strömung
Kurzfassung in englisch
Thermocapillary-driven convection around a gas bubble under a horizontal heated wall is experimentally investigated under gravitational conditions. This physical problem is mainly characterized by a dimensionless number that represents the ratio of convective heat flow induced by capillary convection to the heat transfer due to conduction, which is termed Marangoni number (Mg). In this work, in order to reach very high values of Marangoni numbers, a more concise and sophisticated experimental setup was used, where the experiments were mainly pursued inside a pressure chamber. The experimental work was launched using PIV and shadowgraphy optical measurement techniques. Also, temperature measurements at different flow field locations around the air bubble were conducted to determine the flow behavior at different boundary conditions. This study reveals, that under appropriate conditions, a surface tension driven (thermocapillary) flow can become turbulent. As the Marangoni number increases, the thermocapillary bubble convection traverses several nonperiodic modes until it reaches a turbulent state. We provide empirical equations to express the guideline borders between the different nonperiodic flow mode regimes.
| Universität: | Technische Universität Chemnitz | |
| Institut: | Professur Strömungsmechanik | |
| Fakultät: | Fakultät für Maschinenbau | |
| Dokumentart: | Dissertation | |
| Betreuer: | Wozniak, Günter (Prof. Dr.-Ing.) | |
| ISBN/ISSN: | 978-3-96100-131-6 | |
| URL/URN: | https://nbn-resolving.org/urn:nbn:de:bsz:ch1-qucosa2-749938 | |
| Quelle: | Chemnitz : Universitätsverlag Chemnitz, 2021. - 129 S. | |
| SWD-Schlagwörter: | Turbulenz , Marangoni-Effekt | |
| Freie Schlagwörter (Deutsch): | Marangoni-Konvektion , Nicht-periodische Grenzflächenströmungszustände , Nicht-periodische Strömungoszillationen , Shadowgraph , PIV , Strömungsmodi | |
| Freie Schlagwörter (Englisch): | Turbulence , Thermocapillary bubble convection , Non-periodic flow oscillations , PIV , Temperature fluctuations , Shadowgraphy | |
| DDC-Sachgruppe: | Ingenieurwissenschaften | |
| Sprache: | deutsch | |
| Tag der mündlichen Prüfung | 22.03.2021 | |
| OA-Lizenz | CC BY 4.0 |
