OpenFOAM Fundamentals & Hands on Training

A: Governing principle: y+ = uτ y / ν, with uτ from Cf ~ 0.003 at this Reynolds number. Applied here, uτ lands around 0.8 m/s, giving y ≈ 5e-4 m for y+ ≈ 30. The 50 µm choice traps people who remember the formula but quietly switch to laminar thinking.

A: Governing principle: pressure–velocity coupling must suppress odd–even decoupling on collocated meshes. In this case the checkerboard pattern and delayed divergence line up with missing or incorrect Rhie–Chow treatment. High Co would hurt earlier; low relaxation slows convergence but doesn’t create checkerboarding.

A: Governing principle: solver physics should match driving forces without extra model debt. Here buoyancy and steady operation point straight to buoyantSimpleFoam in a CHT framework. Fully compressible and transient solvers work elsewhere but add failure paths you don’t need under time pressure.

A: Governing principle: adiabatic means no heat flux, but conduction still needs k defined. If the solid region lacks thermal conductivity, energy balance collapses and temperatures wander. Boundary syntax errors show earlier; pressure outlets don’t drive wall temperature drift.