Spatio-temporal evolution of evaporating liquid films sheared by a gas
ORAL
Abstract
Evaporating liquid films under shear are utilized across a wide range of systems,
in which substantial improvements can be made by optimizing the liquid interface's
evolution. We investigated the spatio-temporal evolution of an evaporating liquid
film subjected to a shearing gas, whose effect was prescribed as a constant shear
stress along the liquid interface. Long-wave theory was used to derive an equation
governing the evolution of the liquid interface under the various effects involved.
Linear stability theory was used to investigate the temporal and spatio-temporal
stability of the flow, where it was found that the evaporation and thinning of the
film promotes absolute instabilities and can cause convective-absolute transitions.
Moreover, our model predicts that a strong enough counter-flowing gas suppresses
the inertial instability, arming conclusions found previously for a strongly confined
fllm. Additionally, the governing equation was solved numerically to simulate the film's
evolution subject to finite perturbations, which allowed conducting a numerical spatio-
temporal analysis in the nonlinear regime. Finally, we investigated the role of the
shear stress on the film's rupture dynamics through a self-similarity analysis, which
was validated by comparison to numerical data.
in which substantial improvements can be made by optimizing the liquid interface's
evolution. We investigated the spatio-temporal evolution of an evaporating liquid
film subjected to a shearing gas, whose effect was prescribed as a constant shear
stress along the liquid interface. Long-wave theory was used to derive an equation
governing the evolution of the liquid interface under the various effects involved.
Linear stability theory was used to investigate the temporal and spatio-temporal
stability of the flow, where it was found that the evaporation and thinning of the
film promotes absolute instabilities and can cause convective-absolute transitions.
Moreover, our model predicts that a strong enough counter-flowing gas suppresses
the inertial instability, arming conclusions found previously for a strongly confined
fllm. Additionally, the governing equation was solved numerically to simulate the film's
evolution subject to finite perturbations, which allowed conducting a numerical spatio-
temporal analysis in the nonlinear regime. Finally, we investigated the role of the
shear stress on the film's rupture dynamics through a self-similarity analysis, which
was validated by comparison to numerical data.
*LB and OM would like to acknowledge the Turkish National Research Agency (TÜBITAK) for supporting this work under project 216M001. LB and MD would like to thank TÜBITAK for the 2221 Visiting Fellowship (1059B211800297) through which this work had signicantly gained momentum.
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Publication: O. A. A. Mohamed, M. C. Dallaston & L. Biancofiore, Spatio-temporal evolution of evaporating liquid films sheared by a gas, Phys. Rev. Fluids., 2021, submitted.
Presenters
-
Luca Biancofiore
- Bilkent Univ