Effect of shear stress and gravity on rupture of a locally heated liquid film

O. A. Kabov, D. V. Zaitsev

Research output: Contribution to journalArticlepeer-review

31 Citations (Scopus)


Thin liquid films driven by a forced gas/vapor flow (stratified or annular flows) (i.e., shear-driven liquid films in a narrow channel) are promising candidates for an innovative cooling technique optimizing the trade-offs between performance and cost. The present work is a part of the MAP BOILING program of the European Space Agency and a part of the preparation of the SAFIR experiment onboard the International Space Station. The paper focuses on the recent progress that has been achieved by the authors through conducting experiments with locally heated shear-driven and falling liquid films. Rupture of the liquid film was investigated, and it was found that scenario of film rupture differs widely for different flow regimes. The critical heat flux is ∼ 10 times higher for a shear driven film than that for a falling liquid film and reaches 250 W/cm2 in experiments with water at atmospheric pressure. Rupture of a subcooled falling liquid film heated from the substrate is preceded by the formation of steady-state film surface deformations. The film spontaneously ruptures at the moment when the film thickness in the thinned region reaches a certain critical minimum independent of both the Reynolds number and the plate inclination angle (gravity force). By means of high-speed imaging, it is found that the process of rupture involves two stages: (i) abrupt film thinning down to a thin residual film and (ii) rupture and dryout of the residual film. As the plate inclination angle is reduced, the threshold heat flux required for film rupture weakly decreases; however, when the angle becomes negative, the threshold heat flux begins to rise dramatically, which is associated with an increase of the stabilizing hydrostatic effect due to the growth of the film thickness. Procedures to organize a gas shear-driven liquid film flow under variable gravity conditions (parabolic flights) have been verified. It was found that the flow dynamics in normal gravity differs significantly from that in microgravity; in particular, the film is wavier under low-gravity conditions.

Original languageEnglish
Pages (from-to)249-266
Number of pages18
JournalMultiphase Science and Technology
Issue number3
Publication statusPublished - 2009

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Modelling and Simulation
  • Engineering(all)

Fingerprint Dive into the research topics of 'Effect of shear stress and gravity on rupture of a locally heated liquid film'. Together they form a unique fingerprint.

Cite this