Three-dimensional Simulation of the Dynamic Yarn Behavior on Air-jet Looms

Abstract

This paper deals with the three-dimensional computer simulation of the weft insertion process as a possible solution to avoid costly weaving trials when researching this process. A three-dimensional mathematical model of the yarn was developed, in which the behavior of the yarn was described by the Second Law of Newton. For this mathematical model, a second order differential equation needed to be solved. To this end, an explicit integration using Euler’s method was chosen. In order to validate the model, high-speed camera recordings were performed on a test stand and compared with simulations of the same test stand. A very good resemblance was found between simulation and camera recordings. This is the first time that a three-dimensional model for the weft insertion on air-jet looms has been successfully tested.

Simulation of air flow–yarn interaction inside the main nozzle of an air jet loom

“…In De Meulemeester et al. 11 the tests which were carried out to measure these properties are explained in detail.…”

“…The structure model which is employed in this work is the same as in De Meulemeester et al., 11 with wall contact improvements and bending forces added. The yarn is represented by a three-dimensional model which consists of a chain of line segments.…”

“…The tensile forces are calculated as in De Meulemeester et al. 11 and bending forces as in Baraff and Witkin. 17 For the contact it is affordable to detect contact of every node with every surface as only a limited number of mathematical objects likes boxes, cones, cylinders, and tori are used in the simulations.…”

Simulation of Motion of Long Flexible Fibers with Different Linear Densities in Jet Flow

“…For the flexible fiber, the period of rotation decreases rapidly with the growth of bending deformation of the fiber and rotation orbits deviate from a circular one for the rigid fiber. De Meulemeester et al [3] tried to study the dynamic properties of fiber movement and developed a one-dimensional mathematical model, in which the behavior of the fiber is described by Newton's second law. Lindström and Uesaka [4] proposed a model for flexible fibers in viscous fluid flow; namely, the fibers are modeled as chains of fiber segments which interact with the uid through viscous and dynamic drag forces.…”

“…A correlation is formulated to quantify the relationship between the damping coe cient of the local bond and that of the exible ber. Meulemeester et al [9] developed a threedimensional mathematical model of the yarn.…”