Multiphysics coupling is one of the most challenging problems in engineering simulation. This article introduces the technical approach of the ExCAE independent solver for fluid-structure interaction (FSI) and thermo-mechanical coupling.

What Is Multiphysics Coupling?

In real engineering problems, more than one physical phenomenon is often at play. For example:

  • Aircraft wings deform under aerodynamic loads (fluid-structure interaction)
  • Engine components experience thermal expansion at high temperatures (thermo-mechanical coupling)
  • Acoustic waves propagate through structures (acoustic-structure coupling)

Coupling Strategy Comparison

Strategy Advantages Disadvantages
One-way coupling Low computational cost Ignores feedback effects
Two-way weak coupling Good convergence Limited accuracy
Two-way strong coupling Highest accuracy High computational cost

ExCAE Solution Approach

The ExCAE independent finite element solver supports the following multiphysics coupling capabilities:

Fluid-Structure Interaction (FSI)

Using an ALE (Arbitrary Lagrangian-Eulerian) description-based FSI algorithm, supporting:

  • Two-way coupling of incompressible fluids and elastic structures
  • Mesh updating under large deformation conditions
  • MPI-based parallel solving

Thermo-Mechanical Coupling

Supports steady-state and transient thermal analysis, including:

  • Heat conduction, convection, and radiation boundary conditions
  • Temperature-dependent material properties
  • Superposition of thermal and mechanical strains

Application Case

In the analysis of aerospace engine turbine blades, the ExCAE solver successfully simulated the fully coupled process of high-temperature gas flow, blade temperature field distribution, and thermal stress distribution.


Want to learn more? Contact the ExCAE team for a technical white paper.