การจำลองการอัดรีดสำหรับมวลผงเปียกในกระบวนการเภสัช / ก่อกิจ ธีราโมกข์ = Simulation of extrusion for wet powder masses in pharmaceutical process / Gawkij Teeramoke
In this thesis, the simulation of two dimensional axisymmetric flows with an Oldroyd B model for stick-slip and die-swell problems in extrusion processes is determined. The die-swell problem is applied in polymeric industry and drug manufactory, especially in the step of transformation from wet powder masses to pellets. The simulations of stick-slip and die-swell problems are set up in the forms of the Navier-Stokes and constitutive equation. The numerical method in the name of the semi-implicit Taylor-Galerkin/pressure-correction finite element scheme is used for solving the mathematical model. The condition of slip effect at die wall is adjusted after free surfaces are computed. In addition, the Streamline-Upwind/Petrov-Galerkin method is utilized to improve the stability under the assumptions of isothermal, incompressible, laminar and creeping flows. The numerical results of the simulation problems are compared with the experiment and other literatures.
