喷气涡流纺喷嘴内部三维流场的数值研究

Numerical study of three-dimensional flow field inside the nozzle of air jet vortex spinning

采用3D CFD建立喷气涡流纺喷嘴结构模型,应用Fluent 6.2流体计算软件对模型内气流场进行数值模拟,表征了喷嘴内部三维流场的流动状态,解析了喷嘴内气流流场的压力场和速度场分布,分析了流场与成纱机制的相关关系。研究表明:压缩气流经喷孔后在喷嘴内形成三维旋转气流,切向、轴向气流速度分布符合旋转气流理论;切向气流对边缘自由端纤维加捻,轴向气流对纤维束的牵伸作用可忽略,径向气流对纤维束起膨胀作用,在切向气流作用下获得更多的包缠纤维;喷嘴内部静压呈U形分布;边缘自由端纤维在不同位置加捻程度的差异导致纱线捻度不匀。

A three-dimensional computational fluid dynamics model was developed to simulate the flow field inside the nozzle of air jet vortex spinning with 3-D CFD ＆ Fluent 6.2. Flowing state, distributing of static pressure and velocity inside the nozzle of air jet vortex spinning were characterized and analyzed. Relationship between flowing state and structure of the yarn was also discussed. The research shows that compressive air through the jet orifice comes into being three-dimensional whirly airflow inside the nozzle, the tangential airflow and the arial airflow are fit for the theory of swirling airflow, the tangential velocity twists open-trail end edge fibers ; the draw effect of the axial velocity to fibers may be neglected ; the radial velocity makes the edge opentrail end fibers in the main nozzle begin to expand to let yarn get more wrapper fibers, static pressure distributions take on the U shape along nozzle radius, the reason of twist irregularity of air jet vortex yarn is the degree twisted at different position is different for separated edge open-trail end fibers.