Title: Measurement of the vapor layer under a dynamic Leidenfrost drop

Abstract

To understand the Leidenfrost phenomenon, which is the results of formation of a thin vapor layer, the progression of the vapor should be analyzed. However, due to the limitation of measuring techniques, the empirical measurement of the vapor layer under a dynamic Leidenfrost drop as a function of time has not been reported because the vapor is only tens of micrometers thick and forms within a tenth of a millisecond. Therefore, this paper presents a synchrotron X-ray imaging with the precise resolution to overcome the limitation of previous measurement technique. The liquid-vapor interfacial behavior of a drop of ethanol that is being levitated above a flat SiO₂ surface by the Leidenfrost phenomenon is analyzed depending on surface temperature. Measurements suggest that a thin (< 2 μm) vapor layer develops between the surface and the drop; i.e. that the liquid does not contact the solid. The measured thickness of this vapor layer under a dynamic Leidenfrost drop was less than the thickness of the vapor layer estimated by analytical solution of a model of vapor layer thickness for a static Leidenfrost drop. As a result, the new technique presented in this study will support transient numerical simulations or an analytical solutionmore » of the vapor layer under a dynamic Leidenfrost drop, and may have applications in research on the effects of artificial surface structure on the Leidenfrost phenomenon.« less

Authors:

Lee, Gi Cheol ^[1]; Noh, Hyunwoo ^[1]; Kwak, Ho Jae ^[1]; Kim, Tong Kyun ^[1]; Park, Hyun Sun ^[1]; Fezzaa, Kamel ^[2]; Kim, Moo Hwan ^[1]

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+ Show Author Affiliations

1. Pohang Univ. of Science and Technology, Pohang (Republic of Korea)
2. Argonne National Lab. (ANL), Argonne, IL (United States)

Publication Date:

Tue Apr 24 00:00:00 EDT 2018

Research Org.:

Argonne National Lab. (ANL), Argonne, IL (United States)

Sponsoring Org.:

National Research Foundation of Korea (NRF); USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1478506

Grant/Contract Number:  

AC02-06CH11357

Resource Type:

Accepted Manuscript

Journal Name:

International Journal of Heat and Mass Transfer

Additional Journal Information:

Journal Volume: 124; Journal Issue: C; Journal ID: ISSN 0017-9310

Publisher:

Elsevier

Country of Publication:

United States

Language:

English

Subject:

42 ENGINEERING; Liquid-solid contact; Film boiling; Nucleation; Synchrotron X-ray imaging; Vapor layer progression