The long-standing puzzle of why two colliding bubbles in an electrolyte solution do not coalesce immediately upon contact is resolved. The water film between the bubbles needs to be drained out first before its rupture, i.e.
View Article and Find Full Text PDFAn analytical solution for the sound and elastic waves generated by a rigid sphere with a shell made of elastic material submerged in an infinite fluid is introduced. The sphere oscillates up and down at a fixed frequency and generates elastic waves (both longitudinal and transverse) in the shell, which are then transmitted to the fluid. The effects of the acoustic boundary layer are included (thus, no implicit arbitrary "slip" on the surface as in the usual fluid acoustic model is present).
View Article and Find Full Text PDFPhys Rev Lett
September 2021
We investigate thin film drainage between a viscous oil drop and a mica surface, clearly illustrating the competing effects of Laplace pressure and viscous normal stress (τ_{v}) in the drop. τ_{v} dominates the initial stage of drainage, leading to dimple formation (h_{d}) at a smaller critical thickness with an increase in the drop viscosity (the dimple is the inversion of curvature of the drop in the film region). Surface forces and interfacial tension control the last stage of film drainage.
View Article and Find Full Text PDFJ Opt Soc Am A Opt Image Sci Vis
February 2020
An efficient field-only nonsingular surface integral method to solve Maxwell's equations for the components of the electric field on the surface of a dielectric scatterer is introduced. In this method, both the vector wave equation and the divergence-free constraint are satisfied inside and outside the scatterer. The divergence-free condition is replaced by an equivalent boundary condition that relates the normal derivatives of the electric field across the surface of the scatterer.
View Article and Find Full Text PDFJ Opt Soc Am A Opt Image Sci Vis
February 2020
A field-only boundary integral formulation of electromagnetics is derived without the use of surface currents that appear in the Stratton-Chu formulation. For scattering by a perfect electrical conductor (PEC), the components of the electric field are obtained directly from surface integral equation solutions of three scalar Helmholtz equations for the field components. The divergence-free condition is enforced via a boundary condition on the normal component of the field and its normal derivative.
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