HomeCFD & Mesh QualityCell Aspect Ratio

📐 Mesh Cell Aspect Ratio

Calculate the aspect ratio for triangular, quadrilateral, tetrahedral, and hexahedral grid cells.

⚡ Fortran 90 Engine Double Precision (IEEE 754) ✓ ISO / ASME Validated
Mesh Cell Aspect Ratio Cfd
📊 Solver Telemetry ● ACTIVE
👁️ Views 16
⚡ Solves 12
💾 Downloads 495 📦 Fortran Code 4.4 KB
📅 Released Jun 2026
⏱️ Latency < 1 ms
⚡ TOOLS & REPORTS:
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Mesh Elements: Ideal Equilateral Triangle (AR = 1.0) Stretched Boundary Layer Triangle (AR ≈ 8.0) Ideal Square Quad (AR = 1.0) Prism Layer Stretched Wall Quad (AR = 20.0)

📥 Cell Vertices $(x, y)$

📖 Formulation (Gupta §5.1.1): $$\text{Triangle: } AR = \frac{L_{\text{max}}}{2\sqrt{3}\, r}, \quad r = \frac{2 A}{P}$$ $$\text{Quad: } AR = \frac{\max(\bar{e}_{13}, \bar{e}_{24})}{\min(\bar{e}_{13}, \bar{e}_{24})}$$
4.69
Inradius / Opposite AR
1.94
Edge Ratio ($L_{\text{max}}/L_{\text{min}}$)
4.0000
Cell Area ($A$)
16.246
Perimeter ($P$)
💡 Mesh Quality Assessment: Acceptable (Core Flow)
Aspect Ratio is 4.69 (Edge Ratio: 1.94). High aspect ratio elements are acceptable in boundary layer prisms aligned with wall-parallel streamlines, but should be avoided in isotropic core flow.

📐 2D Element Geometry & Inscribed Circle Visualizer

Acceptable (Core Flow)
🔍 View Raw GNU Fortran Double-Precision Solver Output
At line 65 of file aspect_ratio.f90 (unit = 5, file = 'stdin')
Fortran runtime error: End of file

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📘 Calculation Methodology: Mesh Cell Aspect Ratio

Mathematical Model & Theory

Aspect ratio ($AR$) quantifies stretching of a grid cell along principal coordinate directions. High aspect ratio cells in regions with multi-directional gradients degrade linear solver convergence:

$$AR = \frac{\max(\Delta x, \Delta y, \Delta z)}{\min(\Delta x, \Delta y, \Delta z)}$$
$$AR_{wall} = \frac{\Delta x_{streamwise}}{\Delta y_{wall}}$$

Assumptions

  • Orthogonal or quasi-orthogonal structured/unstructured cells.
  • High aspect ratios ($AR > 100$) are acceptable only where wall-normal gradients dominate.

Academic References

  1. Hirsch, C.: Numerical Computation of Internal and External Flows, Wiley.
  2. Versteeg, H. K., & Malalasekera, W.: An Introduction to CFD, Pearson.

Worked Engineering Example

Problem Statement:
A boundary layer cell has streamwise length $\Delta x = 2.5\text{ mm}$ and wall-normal height $\Delta y = 12.5\ \mu\text{m}$. Calculate aspect ratio.

Step-by-step Solution:
1. $AR = 2.5\text{ mm} / 0.0125\text{ mm} = 200$.
Final Result:
Cell aspect ratio is 200:1.