Understanding interfacial behaviour during boiling of nitrogen from liquid-liquid contact plane

In this paper, a combined photographic and thermal study of interfacial behaviour during boiling of liquid Nitrogen (LN2) over the water surface is reported. As a phenomenon, film boiling behavior is observed and the same is compared with the available correlations in literature. Apart from boiling, during experiments of LN2 drop over water of low temperature, icing has been observed which changes the overall interfacial activities. Rayleigh-Taylor instability (RTI) based criterion has been used to differentiate between regimes which are no bubbling, moderate and vigorous bubbling, based on the release of nitrogen vapor (N-2) from the entrapped liquid layers. No bubbling behavior is observed when the equivalent diameter of the LN2 drop is lesser than the critical wavelength and the generated vapor flux during boiling is sufficient to levitate the drop. The N(2 )vapor cloud generated over the drop is also characterized by optical measurement to relate opacity and temperature. At the end, the phenomenon of sub-surface boiling is also reported through experiments of LN2 boiling over base fluids other than water. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

This paper presents a combined photographic and thermal study of interfacial behavior during boiling of liquid Nitrogen (LN2) over water surface, with observations of film boiling and LN2 drop icing. The Rayleigh-Taylor instability criterion is used to differentiate between bubbling regimes and analyze the N(2) vapor cloud generated over the drop. Sub-surface boiling phenomenon is also reported through experiments on base fluids other than water.