Allows the use of legacy, highly-optimized standalone fluid and structural codes.
FEA inherently excels at handling highly irregular, complex geometries without losing accuracy.
Add artificial, mathematically consistent stabilization terms (such as SUPG or PSPG) to allow equal-order linear interpolations ( Numerical Stabilization Techniques
Re=ρULμcap R e equals the fraction with numerator rho cap U cap L and denominator mu end-fraction
The benefits of using FEA in fluid dynamics are numerous:
| Feature | Traditional FEA (Solids) | Traditional CFD (Fluids) | | :--- | :--- | :--- | | | Finite Element Method (FEM) | Finite Volume Method (FVM) | | Primary Variable | Displacement | Velocity & Pressure | | Conservation | Satisfied globally (weak form) | Satisfied locally per cell | | Mesh Motion | Small deformation (usually) | Often stationary or rigid body motion | | Software | ANSYS Mechanical, Abaqus, Nastran | ANSYS Fluent, OpenFOAM, Star-CCM+ |
When fluid velocities increase, the convective term dominates over the viscous term. The dimensionless quantifies this relationship:
When fluids move extremely slowly (high viscosity, low inertia), the non-linear terms in the Navier-Stokes equations drop out. FEA handles these "linear" viscous problems very well (e.g., polymer extrusion, glass forming, lubrication).
ρ(𝜕u𝜕t+u⋅∇u)=−∇p+μ∇2u+frho open paren the fraction with numerator partial bold u and denominator partial t end-fraction plus bold u center dot nabla bold u close paren equals negative nabla p plus mu nabla squared bold u plus bold f is the fluid density. is the static pressure field. is the dynamic molecular viscosity. is the body force vector field (such as gravity). 3. The Convective Challenge
