振动场对聚合物熔体在异型材挤出口模内的流动影响

Effect of Oscillation Field on Polymer Melt Flow in Extrusion Die of Profile

利用ANSYS软件对受口模入口处周期性振动的压力驱动的非牛顿幂率聚合物熔体在"Y"型异型材挤出口模内的流动过程进行了三维等温数值模拟。研究了入口压力的振动参数对流场压力和速度的影响情况。结果表明:流场中压力和速度的振动频率与入口压力的振动频率相等,而流场压力和速度的振幅随入口压力振幅的增大或者频率的降低而增大,亦即低频高幅的振动容易得到较大的振动幅值。研究还表明流场速度的振动滞后于压力,且速度振动的衰减也比压力的衰减慢。

The three dimensional isothermal numerical simulation was conducted by means of the ANSYS software package for non-Newtonian power-law polymer melt flow driven by periodically oscillating entrance pressure through the extrusion die with an ＂Y＂ shaped cross section. The effect of the oscillate parameters of entrance pressure on the field of velocity and pressure was studied. The results of numerical simulation showed the oscillate frequency of the velocity and pressure of the polymer melt was equal to the frequency of the entrance pressure, but the amplitude of the velocity and pressure increased with the increase of the amplitude of entrance pressure, or to the decrease of the frequency of the entrance pressure. Scilicet, biggish amplitude could be gained by means of the oscillation with a low frequency and a high amplitude. The result also showed the oscillation of velocity was lagged behind the oscillation of pressure, and the attenuation speed of the oscillation of velocity was lower than that of pressure.