Imperial College London

ProfessorChristosMarkides

Faculty of EngineeringDepartment of Chemical Engineering

Professor of Clean Energy Technologies
 
 
 
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Contact

 

+44 (0)20 7594 1601c.markides Website

 
 
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Location

 

404ACE ExtensionSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Charogiannis:2018:10.1103/PhysRevFluids.3.114002,
author = {Charogiannis, A and Denner, F and Van, Wachem B and Benoit, S and Kalliadasis, S and Markides, C},
doi = {10.1103/PhysRevFluids.3.114002},
journal = {Physical Review Fluids},
title = {Experimental investigations of liquid falling films flowing under an inclined planar substrate},
url = {http://dx.doi.org/10.1103/PhysRevFluids.3.114002},
volume = {3},
year = {2018}
}

RIS format (EndNote, RefMan)

TY  - JOUR
AB - We report on detailed and systematic experiments of thin liquid films flowing as a result of the action of gravity under an inverted planar substrate. A measurement technique based on planar laser-induced fluorescence (PLIF) was developed and applied to a range of such flows in order to provide detailed space- and time-resolved film-height information. Specifically, the experimental campaign spanned three inclination angles (β=−15, −30, and −45, in all cases negative with respect to the vertical), two water-glycerol solutions (with Kapitza numbers of Ka=13.1 and 330), and flow Reynolds numbers covering the range Re=0.6–193. The collection optics were arranged so as to interrogate a spanwise section of the flow extending about 40mm symmetrically on either side the centerline of the film span (80mm in total), at a distance 330 mm downstream of the flow inlet. A range of flow regimes, typically characterized by strong three dimensionality and pronounced rivulet formation, were observed depending on the imposed inlet flow conditions. In the lower liquid Kapitza number Ka(=13.1) flows and depending on the flow Re, the free surface of the film was populated by smooth rivulets or regular sequences of solitary pulses that traveled over the rivulets. In the higher liquid Ka(=330) flows, rivulets were observed typically above Re≈30, depending also on the inclination angle, and grew in amplitude until quasi-two-dimensional fronts developed intermittently that were associated with distinct thin-film regions of varying length and frequency. These regions are of particular interest as they are expected to affect strongly the heat and mass transfer capabilities of these flows. The occurrence of the fronts was more pronounced, with higher wave frequencies, in film flows at smaller negative inclinations for the same flow Re. The rivulet amplitude was found to increase at larger inclinations for the same Re and showed a nonmonotonic trend with in
AU - Charogiannis,A
AU - Denner,F
AU - Van,Wachem B
AU - Benoit,S
AU - Kalliadasis,S
AU - Markides,C
DO - 10.1103/PhysRevFluids.3.114002
PY - 2018///
SN - 2469-990X
TI - Experimental investigations of liquid falling films flowing under an inclined planar substrate
T2 - Physical Review Fluids
UR - http://dx.doi.org/10.1103/PhysRevFluids.3.114002
UR - http://hdl.handle.net/10044/1/64715
VL - 3
ER -