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ISSN Online: 2377-424X

ISBN Print: 978-1-56700-474-8

ISBN Online: 978-1-56700-473-1

International Heat Transfer Conference 16
August, 10-15, 2018, Beijing, China

HEAT TRANSFER INVESTIGATION ON A SINGLE ARTIFICIAL NUCLEATE SITE: INFLUENCE OF THE WALL ORIENTATION ON THE BUBBLE BEHAVIOR

Get access (open in a dialog) DOI: 10.1615/IHTC16.bae.024595
pages 1249-1258

Resumo

The purpose of this study is to contribute to a better understanding of the heat transfer in nucleate boiling regime. The aim is to determine the characteristic parameters of the heat transfers when a vapor bubble is created in its liquid on a heated wall by phase change. An experimental device was realized to perform boiling experiment with FC-72 on flat heating wall at different conditions of the wall orientation going from 0°(upward facing wall) to 180° (downward facing wall). This device allows the instantaneous heat flux and the wall temperature measurement. In order to get a better understanding of the mechanisms the simplest situation corresponding to a single artificial nucleation site has been adopted. The obtained results allow bringing to light the phenomenon of nucleation, growth, and detachment of vapor bubbles on a single artificial nucleate site located in the center of the wall. The results of the influence of the heat flux as well as the orientation of the heating wall on departure frequency and heat transfer of generated vapor bubbles are presented and analyzed. We evidenced that the bubble behavior and the heat transfer mechanisms are dependent on the wall orientation with regard to the gravity. Indeed the experiments for several wall inclinations revealed the strong effect of this parameter on the heat transfer in presence of liquid vapor phase change for a single nucleation site.