ELECTROHYDRODYNAMIC DEFORMATION OF A PARTICULATE STREAM BY A TRANSVERSE ELECTRIC-FIELD

A theory is presented for the electrohydrodynamic deformation of a thi n fluid stream and applied to the experiments of Rhodes, Snyder, and R oberts on colloidal dispersions. The resulting transverse velocity fie ld has a symmetric four-lobe structure and, when the conductivity of t he sample is greater than that of the surrounding fluid, the sample de forms into a ribbon whose axis is parallel to the incident field. The ribbon axis is perpendicular to the field if the conductivities are re versed. Electrohydrodynamic velocities are of the order of microns per second and the theory agrees with the qualitative and quantitative fe atures of existing experimental data.