Overview
This section outlines the core assumptions, meshing strategy, and solver settings used to simulate flow-induced stress. The goal is to provide a clear, readable record of the methodology-making it easier to reproduce results and validate the model.
Meshing & Discretization
The mesh was generated using a hexahedral core strategy with localized refinement at weld fillets and interface junctions. This approach balances computational cost with boundary layer resolution, ensuring that the first-layer cell height is controlled to achieve a y+ value of ~1.
Key metrics
Total cell count: 12.4 million elements. The mesh is designed to support transient simulations with minimal numerical diffusion while maintaining a stable CFL condition.
Turbulence & Physics
The simulation employs the SST k-omega turbulence model with curvature correction. The PISO pressure-velocity coupling scheme is selected for stable transient formulation, and the time-step size is restricted to 1e-4 seconds to capture higher-order pressure harmonics.
Boundary conditions
Fixed piping support constraints are applied at anchor points matching physical structural hangers. A cyclic time-series pressure load is mapped dynamically using spatial interpolation to capture localized structural deflection.
Fatigue Evaluation
High-cycle fatigue evaluation is performed based on the ASME Boiler and Pressure Vessel Code Section VIII Div 2. Multi-axial fatigue is resolved using the Goodman relation and Rainflow cycle counting algorithms.
Post-processing
Results are extracted for key locations and summarized in a fatigue damage report. This includes stress cycles, usage factors, and critical locations identified by the solver.
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