Formation and stabilization of an EHD jet from a nozzle with an inserted non-conductive fibre

The formation and stabilisation of an EHD jet from a nozzle with an inserted non-conductive fibre were investigated. The fibre introduced two main effects. First the fibre eliminated backflow in liquid meniscus and allowed the electric field only to accelerate the liquid, while using common capillary nozzle required electric field to overcome the kinetic velocity by convection. Second the accelerating of shear electric stress acted on the liquid surface while the liquid was flowing along the fibre, which did not exist in common nozzle. The above two factors all helped to reduce the potential needed to obtain cone-jet mode, and the second effect highly stabilized the spraying. Among high flow rate range, the influence induced by fibre became significant. Also results show for the same flow rate applied potential affected the thickness of liquid layer on fibre surface slightly. In addition, using the present nozzle intermittent spraying could be obtained and controlled by application of pulsed electric potential.