Numerical Simulation and Experimental Research of Fiber Motion in Vortex Spinning

The application of high speed air-flow in textile field represents the frontier development direction in this field. However, the coupling mechanism between airflow and fiber is extremely complicated which greatly limits the development and application of new textile technologies. For this reason, this research intends to focus on the common cutting-edge basic scientific problem of airflow-fiber coupling mechanism, the vortex spinning technology is taken as a breakthrough point for research. 3D numerical models of airflow in vortex spinning nozzle and a free-end fiber were established. The hybrid grids including the structured hexahedral grids and the unstructured tetrahedral grids were used to divide the airflow computational region, the Realizable κ-ε model was used to solve the turbulent characteristics of airflow, and the wall function method was used to solve the airflow in the near wall region, the displacement and deformation of a single free-end fiber under the action of the airflow force was solved by the second-order nonlinear double asymptotic method and interpolation method. The dynamic twist process of a free-end fiber was simulated in 3D space by taking into account the fiber characteristics, such as straightening, bending and torsion. In addition, a high magnification microscope was used to observe the free-end fiber motion during the spinning process. The results show that the numerical simulation is consistent with the experimental observation, proving that dynamic numerical simulation can solve difficult problems in the unobserved dynamic twisting process, and it deepens the understanding of the spinning mechanism in vortex spinning.