Multiphysics Coupling
Real components obey several physics at once; multiphysics coupling solves them together so their interactions are captured.
One component, many physics
A fusion wall segment is heated by particle flux, stressed by that heat, subject to magnetic forces, and irradiated by neutrons — all at once. Treating each physics in isolation misses the ways they feed back on one another. Multiphysics coupling solves the interacting problems together.
How coupling is done
- Monolithic: assemble all physics into one large system and solve simultaneously.
- Partitioned: solve each physics with its own solver and exchange data between them.
- Each approach trades stability, accuracy, and software complexity differently.
The feedback that matters
Coupling captures effects a single-physics model cannot. Heat changes material properties, which changes stress; magnetic forces change geometry, which changes fields. When these loops are strong, ignoring them gives an answer that is not just imprecise but qualitatively wrong.
Consistency and convergence
Partitioned schemes must iterate until the coupled fields agree at their shared boundaries; stopping too early leaves the physics inconsistent. Verifying that a coupled solution has actually converged — not just each solver individually — is a distinct and necessary check.
Why fusion needs it
The environment inside a fusion machine is one of the most demanding multiphysics settings in engineering: intense heat, high fields near 16.84 T peak in the breeder Hyperion, structural loads, and neutron damage acting together. Credible component design depends on modeling these physics as the coupled system they truly are.