Research on the capturing process of yarn-end using lattice Boltzmann method

To address the high labor intensity and low efficiency of manual yarn-end capture in warping workshops, this paper proposes a negative-pressure adsorption method for automatic capture, improving warping efficiency. First, the motion control equations of yarn on package surfaces are established, and the collision forces between the yarn, package, and suction nozzle are analyzed. Second, the yarn–airflow interaction is analyzed using the immersed boundary lattice Boltzmann method based on momentum exchange. Further, the effects of the distance between the package and the suction nozzle, airflow velocity at the nozzle outlet, the rotational speed of the package, and the width of the suction nozzle on yarn-end motion within the airflow field are investigated, followed by a dimensionless analysis to elucidate the governing flow mechanisms. The optimal parameter combination is obtained by multi-objective optimization with the objectives of high efficiency, low air consumption, and controllable over large distances using the Box–Behnken design-based response surface methodology. In addition, the suction nozzle structure is designed and optimized using the finite element method. Finally, by setting up multiple sets of parameter comparison experiments, the optimal parameter combination achieves a high success rate and the highest score, thereby demonstrating the effectiveness of the method.