玄武岩纤维成型区粘性流动过程的数值模拟

Numerical simulation of viscosity-flow process of formation of basalt fiber

玄武岩纤维的成型过程是制备玄武岩纤维的关键 ,研究其流动、传热规律及参数变化对提高玄武岩纤维质量 ,减少断丝 ,增加纤维强度具有重要意义 .通过建立成型过程中流动和传热的数学模型 ,在合理简化后进行数值模拟 ,得出了玄武岩纤维丝根处的温度、速度、粘度的分布以及丝根的几何形状 .计算结果显示 :丝根呈圆锥形 ,距离漏嘴 2 .5mm左右处为上丝根和中丝根的分界点 ;上丝根丝根的半径变化率大于中丝根的半径变化率 ;丝根的几何尺寸与漏嘴直径及最终纤维直径有关 ;中丝根区的速度、温度、粘度的变化率最大 ,是纤维成型的主要区域 ;纤维的固化点取决于纤维与周围环境的换热条件 .

The drawing process of basalt fiber is very important for basalt fiber production. The research on flow and heat transfer in the drawing process makes a contribution to raising basalt fiber quality and strength and avoiding fiber breakage. The numerical model describing heat transfer and flow in the drawing process of basalt fiber production is built. The numerical simulation is made based on the valid simplifications. The geometrical shapes, temperature distribution, velocity distribution and viscosity distribution of fiber cone are given by solving continuity, momentum and energy equations. The results show that fiber cone is a taper and the variation rate of radius of upper fiber cone is bigger than that of middle fiber cone; the shape of fiber cone is related to nozzle diameter and final fiber diameter; fiber formation occurs in the middle cone, in which the variation rate of velocity, temperature and viscosity are the biggest; fiber solidification has relation to cooling condition. The results provide the theoretical basis of choosing and regulating technological parameters in the drawing process.