Numerical study on the effect of geometric parameters of the second nozzle in air-jet spinning

Abstract

The steady three-dimensional swirling flow in the second nozzle of air-jet spinning was calculated using the realizable k-ϵ turbulence model. The effects of the injector diameter, injector number, injection angle and nozzle outlet diameter on the flow and yarn property were investigated. When the injector diameter increases, the velocities increase and the occurrences of the vortex breakdown move towards the injectors, thus increasing the tensile properties of the yarn. There is a similar result on the injector number. A greater injector number can produce high-quality yarn. Although the effect of the injection angle on the velocity distributions is complex, the extent of the reverse flow regions in the upstream and downstream of the injectors increase with increasing the injection angle. The nozzle outlet diameter is also one of the most important parameters. The larger the nozzle outlet diameter, the lower the flow velocity and the smaller the re-circulation zone.