Numerical simulation of a three-dimensional flow field in compact spinning with a perforated drum: Effect of a guiding device

Abstract

Compact spinning with a perforated drum is one of the most important kinds of pneumatic compacting. It utilizes the transverse air force in a perforated drum to condense the fiber bundle in order to effectively eliminate the spinning triangle and improve the qualities of spun yarns. Therefore, the emphasis in research on a flow field in the condensing zone is always on the difficulty of pneumatic compact spinning. In this paper, the three-dimensional flow field of compact spinning of a perforated drum with a guiding device is investigated using Fluent software. First, a three-dimensional model, using AutoCAD Software, of the condensing zone is given. Then, the numerical simulations, by using Fluent software, of the three-dimensional flow field in compact spinning of a perforated drum with three guiding devices (type A, type B, and type C) and without a guiding device are presented, respectively. It is shown that the effective range of the negative pressure in the condensing zone of the compact spinning system with a perforated drum and guiding device increases significantly as compared with that of compact spinning without a guiding device. The flow field distribution is symmetric with respect to the central line of air-suction flume. The fiber strands move toward the center under the left–right symmetric transverse air force, which achieves transverse converging effects. Meanwhile, the static pressure shows a wavy distribution due to the influence of round holes. Furthermore, it is proved that the comprehensive effect of the type C guiding device is the best. Finally, the theoretical results obtained are illustrated by spinning experiments.