Simulation of Non-Return Valve Closure in a Thixomolding Process Utilizing a Magnesium Alloy

The objective of this thesis is to create a simulation model for a non-return valve in a thixomolding process with a magnesium alloy as the material. Modeling goals are to provide insight into the valve operation, as well as design optimization avenues. Model development first involved validation through element size and time step convergence tests. The next step involved determining the role of various operation parameters such as the viscosity density and pressure conditions.  The final step was to evaluate the model adaptability to valve geometry alteration.  The results showed good convergence in the validation portion. The pressure forces generated due to valve body movement and flow of the fluid pass the ring component were the dominant force governing the valve movement. Density measured the strength of the link between the valve body and the ring, governing the amount of momentum transfer. As for viscosity, it was shown to acts as damping to the system. Finally, alterations to the geometry were shown to directly affect the valve closure speed. Improvements to the model are possible by making the viscosity temperature dependent, as well as using experimental results to further verify the physical model.