An optimum design study of the yarn-channel shape of the air-interlacing nozzle by analysis of fluid flow

Abstract

The air-interlacing process provides assurance in the downstream performance in weaving and knitting without changing the properties of the synthetic yarn. The air-interlacing nozzle is an important component for improving the performance in the air-interlacing process. The airflow inside the air-interlacing nozzle is investigated to design an optimum yarn-channel shape of the nozzle. The width and height of the yarn-channel and inlet pressure are the design variables of the air-interlacing nozzle. The design variables are evaluated by the vorticity. The design of experiments (DOE) approach is utilized to study the influence of the nozzle configuration. Minitab is used as a practical and effective tool in optimizing the nozzle geometry to improve performance. Computational simulations of the impinging airflow inside the nozzle are undertaken using ANSYS CFX. The airflow characteristics such as the vorticity, shock wave, and velocity distributions were discussed. Various cross-sectional shapes of the yarn-channel are investigated with the same inlet pressure. The cross-sectional shape of Shape 6 which has high vorticity is observed to find optimal configurations for the nozzle of the air-interlacing process. The design variables of the nozzle are the width and the height of the yarn-channel and the inlet pressure. The reason for the evaluation of the performance of the nozzle is the maximization of the vorticity. The response surface method (RSM) is applied for the shape optimization. The vorticity cannot increase at the high inlet pressure due to the shock wave. The air-interlacing nozzle, with optimum configurations, is verified numerically and experimentally.