Stretching and squeezing of sessile dielectric drops by the optical radiation pressure
CHRAIBI, Hamza
Centre de physique moléculaire optique et hertzienne [CPMOH]
Transferts, écoulements, fluides, énergétique [TREFLE]
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Centre de physique moléculaire optique et hertzienne [CPMOH]
Transferts, écoulements, fluides, énergétique [TREFLE]
CHRAIBI, Hamza
Centre de physique moléculaire optique et hertzienne [CPMOH]
Transferts, écoulements, fluides, énergétique [TREFLE]
< Reduce
Centre de physique moléculaire optique et hertzienne [CPMOH]
Transferts, écoulements, fluides, énergétique [TREFLE]
Language
en
Article de revue
This item was published in
Physical Review E : Statistical, Nonlinear, and Soft Matter Physics. 2008-06-17, vol. 77, p. 066706
American Physical Society
English Abstract
We study numerically the deformation of sessile dielectric drops immersed in a second fluid when submitted to the optical radiation pressure of a continuous Gaussian laser wave. Both drop stretching and drop squeezing are ...Read more >
We study numerically the deformation of sessile dielectric drops immersed in a second fluid when submitted to the optical radiation pressure of a continuous Gaussian laser wave. Both drop stretching and drop squeezing are investigated at steady state where capillary effects balance the optical radiation pressure. A boundary integral method is implemented to solve the axisymmetric Stokes flow in the two fluids. In the stretching case, we find that the drop shape goes from prolate to near-conical for increasing optical radiation pressure whatever the drop to beam radius ratio and the refractive index contrast between the two fluids. The semi-angle of the cone at equilibrium decreases with the drop to beam radius ratio and is weakly influenced by the index contrast. Above a threshold value of the radiation pressure, these ``optical cones'' become unstable and a disruption is observed. Conversely, when optically squeezed, the drop shifts from an oblate to a concave shape leading to the formation of a stable ``optical torus''. These findings extend the electrohydrodynamics approach of drop deformation to the much less investigated "optical domain" and reveal the openings offered by laser waves to actively manipulate droplets at the micrometer scale.Read less <
English Keywords
Opto-hydrodynamics
Radiation pressure
laser
interface
capillarity
drop deformation
Origin
Hal imported