Date of Award

1991

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Chemical Engineering

First Advisor

John R. Collier

Abstract

Since increasing more complex RIM molds are being used in industry, the goal of this research is to develop a model which can be used to predict the dynamic filling front, hot spots, and air entrapment in molds. In this research a method to simulate the RIM process by considering both the filling and curing stages in variously shaped molds for unsteady state three dimensional state cases was developed. This model can be used to predict not only the temperature and conversion changes with time but also the front position changing as a function time. Using given physical and chemical properties of the RIM system, moldability can be determined in advance. The numerical techniques used in this research include adaptation of the SIMPLE algorithm developed by Patankar for a moving front, two phase system with non-negligible inertial effects, and exothermic chemical reaction. This program is designed to be as general as possible. It was developed with the option of using a linear combination of previous and current time step values. The Crank-Nicolson method and multi-dimensional Tri-diagonal matrix algorithm were chosen to deal the finite difference algebraic equations. Although this research only addresses the isothermal mold wall cases, the program does have the capability to deal with isothermal, adiabatic, or anywhere in between. The capability of the program is verified by comparison of the simulation results and experimental data. In addition, program sensitivity analysis is discussed.

Pages

232

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