Coupled Process Modeling of Flow and Transport Phenomena in LCM Processing

In Liquid Composite Molding (LCM) processes, dry fabric preforms are impregnated with a thermoset resin in a closed mold to fabricate a composite. The resin impregnation process is usually accompanied by other phenomena. In this work, we concentrate on transport phenomena such as convection of heat, cure and volatiles that impact the filling process and/or the quality of the manufactured part. Conventional approach to modeling such a flow is to integrate all the involved physics into the numerical solver. The complexity of integrated computational models will increase the computational time and complicate modification of transport and retention models once implemented. The latter particularly complicates the exploratory modeling attempts to uncover additional physics that require fast and easy code modification. We propose and provide an implementation methodology to separately couple transport and flow models. With this approach, one can couple flow simulation using highly specialized simulation tools with associated transport phenomena that use separate implementation. The emphasis is on transport of volatiles, both discrete bubbles and dissolved solvents, but it is equally applicable to other problems, such as particle transport and filtration or cure propagation. The challenge of this approach is to (1) formulate proper models and implement them and (2) solve the communication between models efficiently. In our case, the distinct models can be coupled through data exchange, via standardized message passing interface (MPI). A well-tested and optimized flow simulation tool LIMS (Liquid Injection Molding Simulation) is used to implement the coupled simulation processes and transfer the simulation state in an efficient manner to model other transport phenomena. Coupled models to track distinct particles and/or bubbles of volatiles and implement convected/diffused dissolved volatiles. The results are presented highlighting the feasibility and utility of this methodology.