Numerical Study on the Jet Dynamic through Centrifuge Spinning: Influence of Angular Velocity

Centrifuge spinning is a method that makes possible of fabrication nanofibers rapidly and at high yields. In the centrifugal spinning process, a polymer solution is delivered by the centrifugal force through small nozzle of a rapidly rotating cylindrical drum. Thereby, thin fibers are formed and collected on a collector in the form of a web. In this study, a mathematical model of the dynamics of a viscous liquid jet, which emerges from rotating drum through centrifuge spinning, was derived. The Navier-Stokes equations were solved in this system with the usual viscous free surface boundary conditions. One-dimensional equations were derived using asymptotic methods based upon a slender jet assumption and solved numerically. The effect of angular velocity upon the trajectory, radius, and tangential velocity of the jet was simulated and presented. Increasing angular velocity resulted in a decrease in the size of the liquid jet. Also, increasing angular velocity tended to increase the jet velocity which translated to increase the production rate. The jet centerline became more tightly coiled when the angular velocity increased. In addition, simulated jet diameter was compared with some results reported in our previous work.