Two-Dimensional Modeling of Nonlinear Dynamics of Forcespinning Jet Formation

Abstract

Forcespinning is a novel method that makes use of centrifugal forces to produce nanofibers rapidly and at high yields. To improve and enhance the forcespinning production method, a 2D computational forcespinning inviscid fluid dynamics model is developed. Two models, namely, time-independent and time-dependent, are obtained in order to investigate the effects of various parameters on fiber forcespinning formation (trajectory, jet diameter, tangential velocity). The fluid dynamics equations are solved using the method of multiple scales along with the finite difference method and including slender-jet theory assumptions. It is important to produce jets with small diameters in the micro- and nanorange. Both the Weber (We) and Rossby (Rb) numbers were found to expand the jet trajectory as they increased. Increasing We and/or decreasing Rb was found to decrease the jet diameter. Also, by varying forcespinning parameters, it has been found that the jet radius can be decreased by increasing the jet exit angle in the direction of rotation, reducing the spinneret fluid level, increasing the angular velocity of the spinneret, reducing spinneret length, and/or reducing the orifice diameter. Knowing that jet trajectories are important for designing and positioning of the fiber collector, it has been found that the trajectories expand out with the increase in the jet exit angle in the direction of rotation, increase in the fluid level, increase in the angular velocity, and/or increase in the spinneret length. Production rates and jet radii for any predetermined radial collector distance were also determined.