Mesh Quality¶
After mesh generation, the Mesh Quality tab displays comprehensive quality metrics. Good mesh quality is essential for solver stability and accurate results.
Quality Metrics¶
Skewness¶
Measures how much a cell deviates from its ideal shape (e.g., a perfect hexahedron or tetrahedron).
Range |
Rating |
Impact |
|---|---|---|
0.0 – 0.25 |
Excellent |
Ideal for all solvers |
0.25 – 0.50 |
Good |
No issues expected |
0.50 – 0.85 |
Acceptable |
May slow convergence slightly |
0.85 – 1.0 |
Poor |
Can cause convergence failure |
Target
Maximum skewness should be below 0.85 throughout the mesh. Review highlighted regions before running a simulation.
Non-Orthogonality¶
The angle between the face normal vector and the vector connecting adjacent cell centers. Lower is better.
Range |
Rating |
Impact |
|---|---|---|
0° – 45° |
Excellent |
Fast convergence |
45° – 70° |
Good |
Standard for most solvers |
70° – 85° |
Acceptable |
May need non-orthogonal correctors |
> 85° |
Poor |
Solver instability likely |
Aspect Ratio¶
The ratio of the longest cell dimension to the shortest.
Volume cells: Should generally remain low in the bulk mesh.
Near-wall cells: High aspect ratios can be acceptable when they are intentional and aligned with the wall-resolution strategy.
Cell Volume¶
All cells must have positive volume. Negative or zero-volume cells indicate a mesh error and must be resolved before simulation.
Quality Report¶
The Mesh Quality tab shows:
Summary statistics — Total cell count, min/max/mean of each metric
Histograms — Distribution of cells across quality ranges for each metric
Threshold indicators — Visual markers showing what percentage of cells fall in each quality category
Interpreting Results¶
Healthy Mesh¶
95% of cells rated “Excellent” or “Good”
Maximum skewness < 0.85
Maximum non-orthogonality < 70°
No negative volumes
Marginal Mesh¶
80–95% of cells rated “Excellent” or “Good”
A small number of poor-quality cells (< 1%)
May need non-orthogonal correctors enabled in solver settings
Poor Mesh¶
Many cells with high skewness or non-orthogonality
Likely to cause solver divergence
Consider adjusting mesh settings and regenerating
Improving Mesh Quality¶
If quality is not satisfactory:
Issue |
Solution |
|---|---|
High skewness near geometry |
Increase local or surface resolution. |
High non-orthogonality at transitions |
Smooth the size transition or reduce abrupt refinement jumps. |
Very small cells |
Simplify or repair tiny geometry features and slivers. |
Negative volumes |
Check geometry for self-intersections and repair |
Poor quality in narrow gaps |
Increase local gap resolution or simplify geometry |
Quality vs. Cell Count Trade-off¶
Higher quality generally requires more cells:
More local refinement -> Better resolution where it matters.
Smaller base cell size -> More uniform sizing.
Higher surface resolution -> Better geometry capture near important features.
Balance quality against your cell count budget and available compute credits.
Tip
The AI Assistant can interpret your quality report and suggest specific improvements. Ask: “How can I improve the mesh quality?”