The Research On The Flow Field Simulation Of Rotor Spinning Channel And Dynamic Characteristics Of Rotation Cup

It is an important tendency in the field of spinning equipments that the gas is managed asworking medium for transmission. The rotor spinning is a new spinning technology using gas asworking medium. At present, there is still a large gap between domestic rotor spinningequipments and foreign advanced equipments. The main reason is that the yarn formingmechanism of rotor spinning and design method of high-speed rotation cup are not well studiedin China. The flow characteristics of flow field in rotor spinning channel which is the foundationof studying yarn forming mechanism have an important effect on the conveyance of fibers andthe spinning. The dynamic characteristics of rotation cup which is the important reference ofrotation cup structure design have influence on rotation cup revolving safely, steadily and highspeedily.The rotor spinning channel and rotation cup are taken as the object of this paper. The flowcharacteristics of flow field in rotor spinning channel and dynamic characteristics of rotation cupare studied by using CFD and FEM respectively. It will provide corresponding reference forstudying yarn forming mechanism and rotation cup structure design.The finite element model of rotation cup was established, and the vibration characteristicsof rotation cup and stress distribution of rotation cup with different structures were studied byusing FEM. It is concluded that, with the vibration of rotation cup, the swinging vibration modeproduces firstly, and the lip is the most probable to be damaged; when the degree of the slipplane is less than19.5°, the concave shape deformation is produced probably; the rotation cupwith V-shape accumulation groove is more likely to have concave shape deformation comparedwith U-shape’s.The general nature of flow field in rotor spinning channels was analyzed, and the CFDmodel was established, then the numerical simulation was carried out. It is concluded that, acomplex space spiral flow whose flow direction is bottom-up is formed in rotation cup; thenegative pressure exists in the central area of rotation cup, and its value existed in the exit offiber pipeline is the minimum. Then the air flow characteristics in rotation cup with differentstructures were analyzed. The value of negative pressure which impacts pneumatic conveyance decreases with the increasing degree of slip plane; when≥24.5°, the backflow is formed on slipplane; the concave shape deformation caused by centrifugal force of high speed rotation cupmakes backflow form more easily on slip plane; the airflow distribution of velocity in differenttypes of accumulation groove has no difference.The flow of fibers in fiber pipeline was numerically simulated by using fiber particle model.It is concluded according to analysis that, there is more fibers on up-down wall of pipeline andless fibers on left-right wall of pipeline; the velocity of fibers increases gradually, and theacceleration rises.