Factors affecting dynamic electrical manipulation of menisci

Dynamic electrical manipulation of liquid surfaces, which could be of benefit in electrostatic spraying applications as diverse as crop dusting, ink jet printing, and ion propulsion, is investigated. The authors analyze the dynamics of a conductive meniscus formed of a Newtonian liquid and exposed to an electric field. The significance of mechanical time constants involving surface tension, density, and viscosity are investigated. Dimensionless parameters are used to characterize important aspects of the interactions. Vibrations of an axisymmetric meniscus of an inviscid liquid, confined at the end of a conductive tube, are presented as an example. The dimensionless quantities ε₀E²b/γ and μ²/(ρbγ) appear to be key parameters, where b is the radius of a circular hole defining the meniscus, γ is the surface tension, μ is the viscosity, and ρ is the liquid mass density.