A Region Transformation Algorithm For Fluid Flow In Twin-Screw Extruder

This paper focuses the numerical calculation of the three-dimensional mathematical model of fluid flow in a twin-screw extruder.Since twin-screw extruder is an important equipment for production and processing of materials such as plastic,its mathematical modeling and numerical calculation has been a hot issue.The main difficulty of the numerical calculation is that the fluid flow region is a complex region,whose cross section is a three-connected region changing with time,so that its flow problem is difficult to be solved by traditional methods.For the difficulty,in this paper,the three-connected section region of the twin-screw extruder is smoothly mapped into a three-connected circular boundary region not changing in time,thus the entire flow region is transformed into a solution region not changing in time.This can enable a computational solution on a fixed solution region by some methods such as the finite element method.The above region transformation algorithm and finite element method are used to calculate the initial boundary value problem of a heat conduction with a known exact solution on the fluid flow region of a twin-screw extruder.The calculation results are compared with the exact solution and the error is small,which shows that this region transformation algorithm is feasible.It can be expected that applying this region transformation algorithm to the calculation of fluid flow in the double-screw extruder will yields effective results.