幂律流体三维脉动流场数值模拟

Numerical Simulation of Three Dimensional Pulsate Flow Field with Power-Law Melt Model

利用ANSYS软件,模拟了振动诱导单螺杆挤出机熔体输送段中非牛顿幂律流体的三维脉动流场,得到了三维脉动流场的瞬时速度分布及螺槽中物料的流动轨迹。结果表明,在脉动流场作用下,非牛顿流体的瞬时速度响应与在驱动壁面上所施加的正弦形式的脉动驱动形式不同,横螺槽方向的环流中心位置受幂律指数影响,且发生周期性改变。振动的引入使得在相同的时间内,物料的流动路程增加,且可增大物料的平均停留时间,有利于改善混合效果。

Numerical simulation was implemented for the three-dimensional pulaste melt flow of non-Newtonian power law fluid in the melt conveying section of vibration induced single-screw extruder by means of ANSYS software package. Transient velocity distribution and flow trace of the melt were obtained. The simulation results reveal that the transient response pattern of the velocity of the non-Newtonian fluid is different from that of the sinusoidal driving velocity of the driving surface; the position of the circulation center is influenced by the power law index and changes periodically; the application of vibration to extrusion process results in the increase in flow length within a same period of time and lengthening the residence time of melt so as to improve mixing effect.