纤维在转杯和输纤通道中的运动模拟

Simulation of fiber movement in the rotor and fiber transport channel

为了研究纤维在转杯和输纤通道中的运动,文章在SolidWorks 2018中建立抽气式转杯纺纱通道的物理模型,采用Fluent 19.0与EDEM 2018耦合模拟纤维的运动,探究了纤维长度为1 mm时在输纤通道和转杯中的运动数值分布,模拟了长度为16 mm时纤维在输纤通道中的运动状态。结果表明:当转杯转速为50000 r/min时,纤维在转杯内的速度分布为85.9~89.6 m/s,纤维转动动能分布为2.65×10^(-9)~3.04×10^(-9) J,纤维的受力分布为1.17×10^(-3)~1.22×10^(-3) N,纤维的能量分布为9.67×10^(-6)~1.05×10^(-5) J;输纤通道中的气流场存在压强梯度和速度梯度,纤维在输纤通道中的最大速度在出口处,且在输纤通道中同一时刻气流的速度始终大于纤维的速度,有利于纤维的伸直和输送。在输纤通道与转杯滑移面交接处纤维由于冲击导致的动能向弹性势能转变,速度较低,不利于及时向转杯凝聚槽中输送纤维,容易在转杯滑移面处发生堆积,因此需合理设计该处的几何尺寸,从而为生产实践和机构设计提供了理论依据。

Rotor spinning is a new high-speed and high-efficiency yarn-spinning method with strong fiber adaptability and wide application range.The theory research of rotor spinning process is the basis to improve yarn performance,develop new yarns and upgrade the equipment.To explore the movement of fiber in the rotor and fiber transport channel,the physical model of air extraction rotor spinning channel is established in SolidWorks 2018.The fiber models of 1 mm and 16mm are built by EDEM 2018.By the coupling software of both Fluent 19.0 and EDEM 2018,the numerical analysis of the movement of fibers with the length of 1 mm in the fiber transport channel and rotor is carried out and then the movement of fibers with the length of 16 mm in the fiber transport channel is simulated.In this study,the fluid mechanics method is innovatively used to study the motion characteristics of flexible fibers in the airflow field of the high-speed rotating rotor,which offers a theoretical foundation for the yarn forming mechanism of rotor spinning.The results show that when the speed of rotor is 50000 r/min,the velocity distribution,the rotational kinetic energy distribution,the stress distribution and the energy distribution of the fibers in the rotor are 85.9-89.6 m/s,2.65×10^(-9)-3.04×10^(-9) J,1.17×10^(-3)-1.22×10^(-3) N and 9.67×10^(-6)-1.05×10^(-5) J,respectively.There are pressure gradient and velocity gradient in the air flow field in the fiber transport channel.The maximum velocity of the fiber in the fiber transport channel is at the outlet,and the velocity of the air flow is greater than that of the fiber in the fiber transport channel,which is conducive to the straightening and transport of the fiber.Due to the impact,the kinetic energy of the fibers located at the connections of the fiber transport channel and the slip surface of the rotor changes to the elastic potential energy,leading to the lower speed of the fibers,which is not favorable for the fiber transportation to the rotor collecting groove.Therefore,it is necessary to reasonably design the geometric size of the place.The yarn structure and performance characteristics are determined by the motion characteristics of the fibers in the high-speed rotating rotor.The theoretical research in this paper provides a strong theoretical basis and technical support for the further development of new rotor spinning yarns and optimization of key components with short spinning process,high yarn forming efficiency and strong fiber adaptability.