Numerical simulation of the internal flow field of a new main nozzle in an air-jet loom based on Fluent

Abstract

In order to decrease the turbulence influence and the backflow during weft insertion in an air-jet loom, a new main nozzle composed of two nozzle needles connected in series is designed. The internal flow fields of the commonly used nozzle and the new nozzle are numerically studied by means of a three-dimensional model implemented by the computational fluid dynamics technique. It is observed that the turbulence strength is effectively controlled with different air supply pressures and the backflow phenomenon at the upstream passage generated by high supply pressures can be eliminated when the supply pressure is reasonably distributed into two inlets of the new nozzle. The drag force exerted on the weft yarn is calculated when the velocity distribution of the internal airflow is obtained, and results show that the drag force can be improved. Also, the numerical simulation can give some guidelines for future prototyping and experiments.