Transient VOF CFD simulation tracked resin flow from a storage tank through the supply pipelines and into a porous fibrous preform, predicting the filling pattern, fill time and regions at risk of incomplete impregnation.
Sector
Composite manufacturing
Client
Industrial manufacturer
Flow type
Transient VOF and porous-media flow
Project Snapshot
Challenge
The fibrous preform has far higher flow resistance than the supply piping, so resin slows sharply and can advance unevenly once it enters the fibres. Uneven fronts can trap air and leave dry spots, and the part must be fully wetted before the resin begins to cure. Inlet and vent positions therefore need to be verified before production.
Approach
A transient VOF multiphase model tracked the resin–air interface through the complete system, from tank to pipelines to preform. The fibrous region was represented as a porous medium with permeability-based resistance, so the progression of the resin front and the total fill time could be predicted.
Key Findings
- Filling time was dominated by the porous preform rather than the supply lines, so the permeability of the preform, not the pipe sizing, was the main lever for reducing cycle time.
- The resin front advanced preferentially along lower-resistance paths, leaving regions far from the inlet to fill last.
- Last-to-fill zones were identified as the areas at highest risk of air entrapment and dry spots, which indicated where vents should be placed or inlet locations adjusted.
Deliverables
Transient resin-front animations, fill-time prediction, identification of last-to-fill regions and recommendations on inlet and vent placement for the infusion process.
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