Electric-Field-Controlled Droplet Deformation in a Shear Flow Field
By employing the digital particle image velocimetry method,the electric-field-controlled deformation and rotation characteristics of a droplet in a shear flow field are experimentally studied.The electrohydrodynamic mechanisms of the droplet deformation are revealed and the effects of the electric field and shear flow field on the droplet deformation are summarized.It found that the droplet deformation can be controlled by altering the strengths of the shear flow field and electric field,and the physical parameters of the fluids.when the conductivity ratio of the droplet to the continuous fluid R is larger than the permittivity ratio S,the viscous force cooperates with the electric force and the surface charge convection effect to promote droplet deformation.when R＜S,the electric force and the shear flow force promote the droplet deformation,while the surface charge convection effect reduces it.Besides,a vortex inside the droplet is formed by the shear flow.The vortex intensity is enhanced and reduced by the electric field when R＞S and R＜S,respectvly.
electric fieldshear flow fieldelectrohydrodynamicsdroplet deformation
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