Abstract

A strong microjet is generated in an electro-conjugate fluid between a positive and a ground electrode in a high external electric field. We here elucidate the mechanism and characteristics of this strong microjet by means of lattice Boltzmann simulations. In this analysis, we assume that charges are injected from the surface of a positive electrode at the position of a locally high concentrated electric field. When the effect of the Coulomb force is much more dominant than the viscous force, a strovnng microjet between the positive and the ground electrode is generated. This microjet attains a maximum velocity, collides with the ground electrode and disperses in oblique directions. The flow rate resulting from the appearance of a microjet increases with increasing electric field strength in a proportional manner. The present numerical results in respect to the visualisation of a microjet are in good agreement with a corresponding experiment.