Numerical study of the three-dimensional preliminary flow field in the ring spinning triangle

The spinning triangle is a critical region in ring spinning. To understand the formation principle of the triangle zone, a dynamic mesh model with SIMPLEC algorithm is employed to study airflow around the rotating front roller-pair. The effects of both the top roller offset and the drafting inclination angle are also discussed. The bubble-type vortex breakdown and vortices around two cylinders are observed. The bubble-type vortices will help the edge fibers to converge to the center. A contour line with special value is defined to describe the spinning triangle. A dynamic triangle zone is also observed with time. As the forward offset of the top roller increases, the velocities in the stream-wise (x- and y-) directions decrease and the maximum values of the skin friction deflect gradually towards the apex of the roller. However, the z-velocity for the 3 mm top roller offset is the largest and results in a good converging for fibers and, consequently, increases the yarn tension. With increasing the inclina...