Simulation Of Flow In Kneading Block In Intermeshing Co-Rotating Twin Screw Extruder

This thesis concentrates on simulation of Non-Newtonian isothermal flow in kneading block in closely intermeshing co-rotating twin screw extruders. The kneading block geometry is calculated comprehensively according to kinematics principle and modification of geometry is made to satisfy the practical running condition. A physical model with consideration of both gaps between kneading block and barrel and between kneading disks and real shape of nip region is developed. The real velocity on kneading block surfaces and pressure of both end are applied as boundary condition in FEM analysis. By using a finite element analysis package-ANSYS, velocity profile and pressure profile of kneading block are obtained. Then post processing software were developed to calculate flow rate, backflow, elongation rate, shear rate and shear stress. The influences of rotating speed, pressure difference, stagger angle, gap, width of kneading plate and material parameter were quantified.Further more, the thesis developed simulation in combined region of kneading block and screw elements and simulation in pure screw elements to investigate the influence of kneading block and screw elements on flow region .At last, flow rate, the influence of pressure difference and screw combination on flow rate were confirmed by experiments.