Rotating Fiber Jets during Forcespinning with Aerodynamic Effect

Abstract

Nanofibers are known to have incredible properties and applications in diverse field such as defense, energy, aerospace, filtration, and biotechnology, to name a few. Forcespinning (FS) is a new experimental process that can produce nanoscale fibers under the action of rotating forces. In the usual FS process, a mesoscale fluid jet is forced through an orifice of a rotating spinneret, where the ambient fluid is air. This leads to the formation of a jet with a curved centerline. In this study we apply multiscale and perturbation techniques to investigate rotating fiber jets and their stabilities in the presence of aerodynamic drag force due to the ambient air that is known to exist experimentally in the FS process. First, we calculate numerically the expressions for the leading-order steady solutions for jet quantities such as radius, speed, and trajectory versus arc length, and we determine, in particular, the results for such quantities and their variations in the presence of aerodynamic effect. Next, we calculate the stability of the fiber jet versus temporally growing, spatially growing, or spatiotemporally growing perturbations and determine the results for the growth rates of the effective perturbations versus jet flow parameters.