MESH / 010
Boundary Layer Thickness Estimate
Estimate the boundary-layer scale along a smooth flat plate under idealized zero-pressure-gradient conditions. Use it as a meshing sanity check, not as a substitute for the solved CFD field.
Use the boundary-layer scale to challenge prism-stack thickness.
The first cell sets near-wall resolution; total prism thickness should also make sense relative to the physical boundary-layer scale. This simple flat-plate estimate can provide an order-of-magnitude check before solving.
Estimate first cell height from y+.
Estimate boundary-layer scale at the streamwise location of interest.
Design prism layers with sensible growth and total thickness.
Verify in CFD because pressure gradients, transition, curvature and separation can change the real layer dramatically.
Use the thickness estimate to challenge the near-wall mesh—not to replace it.
The physical boundary-layer scale, first-cell height, prism coverage and solved y+ need to tell a consistent story.