COMPUTATIONAL 2-PHASE AIR FIBER FLOW WITHIN TRANSFER CHANNELS OF ROTOR SPINNING MACHINES/

The pneumatic conveyance of fibers within confined channels is particu larly relevant to textile engineering, with applications such as trans porting individual fibers within rotor spinning machines. The channels of converging shape within these machines are designed to help straig hten the orientation of the fibers that have escaped from the opening roller. This allows a satisfactory configuration of fibers to be prese nted to the spinning rotor surface, which in turn improves yarn and su bsequent fabric properties. In this study, a new air/fiber two-phase m odel is developed to simulate fiber movement within confined channels. The computation is based on the results from single-phase air flow si mulations in a one-way coupling Lagrangian strategy for predicting fib er trajectories. Initial fiber position and the underlying air flow pa ttern are demonstrated to be critical to the final fiber configuration at the exit of the channel. A streamwise straight fiber tends to gene rate a leading hook, while a cross fiber is subject to bending. The ae rodynamic forces very nearly retain the fiber configuration adopted at the channel inlet without significant improvement of fiber straightne ss, since hooks are simultaneously generated and eliminated during tra nsport. Fiber opening and fiber detachment from the opening roller are identified as the two critical factors in obtaining straight fibers a t the channel inlet and their transport to the spinning zone.