Seeing your 2D mesh quality in HENMESH: C/O grids, layers, skew and hand-off

HENMESH is prep, not a solve

HENMESH builds 2D mesh packs for aerospace sections. It reports quality metrics the engine computes. It does not run CFD or FEA. It does not certify meshes for authorities. Every pack carries a method ID so reviewers know which prep recipe you used.

Labelled 2D methods

• HM-MESH-2D-AIRFOIL-CO-001 — Structured airfoil C/O grid — Chord–normal blocks around an airfoil. Leading-edge clustering, wake band and far-field sizing follow aerospace section habits.
• HM-MESH-2D-SECTION-001 — Section domain pack — Outer domain extents and boundary naming aimed at HENFLOW and HENSTRUCT screens — not a blank file without context.

What is a C/O grid?

C/O means Chord–Normal (along the airfoil chord and perpendicular to it). Structured blocks line up in a curvilinear grid wrapped around the section.

• Leading edge (LE) — Cells are often smaller here because curvature is high and pressure gradients are steep.
• Wake band — Extra resolution downstream helps viscous and wake-capture methods downstream in HENFLOW.
• Farfield — The outer boundary should sit far enough away that boundary conditions do not pollute the section. “Far enough” depends on Mach and what you solve next — treat HENMESH defaults as screening habits, not universal rules.

When you rotate the view, check that block lines follow the surface smoothly. Jagged block corners at the LE are a sign to revisit clustering settings before export.

Layer grow (normal layers)

Layer grow adds structured layers off the wall for viscous solves. In plain English: thin prisms stacked normal to the surface so NS-SA or viscous workflows can resolve the boundary layer.

• First layer height — Sets the smallest cell at the wall. It influences y+ (see below).
• Stretch ratio — How fast layers grow outward. Too aggressive growth can jump from wall to core in few cells.
• When layers matter — Panel Euler screens may ignore layers entirely. NS-SA hand-offs need honest layer intent documented on the export.

y+ in plain English

y+ is a non-dimensional wall distance. It tells you whether your first cell sits in the viscous sublayer, the log layer, or somewhere in between — for the turbulence model you plan to use in HENFLOW.

HENMESH may report y+ estimates when the workflow supplies the inputs they need. Rules of thumb:

• Low y+ (order unity) — Often associated with resolving the wall for some turbulence models.
• Higher y+ — Sometimes used with wall functions — model-dependent.

Do not treat a single y+ number on a prep screen as proof the later NS-SA run is correct. Validate in HENFLOW with the same method ID trail and your programme’s checklist.

Skew and aspect ratio colormaps

Quality colormaps paint each cell by a metric. Two common ones:

• Skew (or orthogonality) — How far a cell deviates from a nice rectangle. High skew near the LE or trailing edge (TE) can hurt solver stability and accuracy. Yellow or red zones deserve a mesh tweak before you burn a HENFLOW credit.
• Aspect ratio — How long and thin a cell is. Boundary-layer layers are intentionally thin and long — high aspect ratio there can be normal. Unexpected aspect ratio spikes in the farfield often mean block setup issues.

Always capture the color legend on screenshots. “Red cells” mean nothing without the numeric range.

Farfield and boundary naming

The section domain pack names outer boundaries so HENFLOW cases know inlet, outlet and far-field edges. Good naming keeps the hand-off readable in review: the mesh method ID plus boundary labels tell the story without oral tradition.

Hand-off to HENFLOW and HENSTRUCT

1. Generate mesh with HM-MESH-2D-AIRFOIL-CO-001 or HM-MESH-2D-SECTION-001.
2. Fix skew or aspect flags while still in HENMESH — cheaper than debugging a diverged CFD job.
3. Export toward HENFLOW for flow screens or toward HENSTRUCT when the structural idealisation consumes the same section context.
4. Keep HENFOIL or HENSYNTH geometry references on the slide chain.

HENMESH does not guarantee solver convergence. It gives labelled prep with quality gates appropriate to early design.

What not to claim

• Not authority-approved or certification mesh
• Not a general HyperMesh replacement for every CAD model
• Not proof that y+ targets are met for every turbulence model
• Not a CFD or FEA result — no Cl, no von Mises from HENMESH alone

Further reading (external concepts)

• NASA — spatial discretization and mesh ideas (CFD context)
• NASA Glenn — boundary layer introduction

Related HENDOI reading

• HENMESH product page
• 2D C/O grids and section domains
• HENMESH — aerospace 2D meshing preprocessor
• Read HENFLOW Cp and coefficients
• HENFLOW · HENSTRUCT