异向双螺杆挤出机机头模具内三维流场的数值模拟

Simulation of 3D flow field in Die of Counter-rotating Twin Screw Extruder

利用Polyflow软件包对异向旋转双螺杆的机头模具进行了数值模拟。通过改变工艺参数,对其剪切应力场、剪切速率场、粘度场以及压力场进行比较分析,结果表明在机头模具内,螺杆头的旋转是造成最大剪切应力的原因,转速越大,剪切应力越大；增大流量,同样会增大剪切应力,增加分散混合能力；但流量减少时,剪切应力梯度也会减小,说明物料的混合更均匀。

Numerical simulation for extrusion die of the counter - rotating twin screw extrude with POLYFLOW are performed by changing technical parameter, we obtain the information that the biggest shear stress is made by rotating of extrusion die in the model, the more rotating, and the bigger shear stress ; Meanwhile, enlarging the flowrate will increase the shear stress, which can buildup the ability of distribution and mixture, however, reducing the flowrate will decrease the shear stress gradient, which indicate the uniformity of the material＇s distribution.