On nonlinear rotating electrified non-Newtonian jets

Abstract

We consider a nonlinear non-Newtonian rotating jet flow whose centerline is curved and is elongated by an electric force due to an imposed electric field. The jet is driven both by the imposed electric and rotational forces. We introduce a non-Newtonian viscosity model, which, in particular, takes into account both extension thinning and thickening of the jet. From the governing equations and the boundary conditions of such jet flow, we construct a modeling system based on the slender-body theory for such nonlinear jet and calculate numerically the expressions for the nonlinear steady solutions for the jet quantities such as radius, speed, stretching rate, induced electric field and surface charge versus arc length. We determine these quantities for different values of the parameters that represent effects due to rotation, electric field, electric conductivity, viscosity and relaxation time. We find, in particular, that the jet speeds up, stretches up, and its diameter reduces significantly with increasing the imposed electric force, rotational forces and the jet relaxation time. The notable jet radius reduction that is due to strong electric and rotational effects is found to be for jet dominated by negative surface charge whose magnitude enhances with the rotation rate and the electrical conductivity.