# Moldflow

Moldflow-specific checks used to calculate element quality for 2D and 3D elements.

Additional element checks not listed here are not part of the solver’s normal set of checks, and therefore use HyperMesh check methods.

## 2D and 3D Element Checks

These checks apply to both types of elements, but when applied to 3D elements they are generally applied to each face of the element. The value of the worst face is reported as the 3D element’s overall quality value.
Aspect Ratio
Only applied to triangles, with quadrilaterals given a value of:
$\frac{2.0}{\sqrt{3}}$
This is the same value obtained from an equilateral triangle, and is assigned to quads to prevent HyperWorks CFD from misinterpreting a quad as a badly formed triangular element.
Moldflow calculates a triangle’s aspect ratio by squaring the longest edge of the triangle, and dividing the result by twice the triangle’s area. 1.0 denotes a perfect equilateral triangle.
When applied to 3D elements, the aspect ratio is the ratio between the longest and shortest edges of the tetrahedral element.

## 3D Element Only Checks

Vol. Aspect Ratio
Finds the perpendicular height h of each node, and then dividing the longest edge length L by the shortest height h and multiplying by the square root of 1.5:
$\frac{\sqrt{1.5}×L}{h}$
This results in an equilateral tetrahedron having a volume aspect ratio of 1.5. Non-tetrahedral elements are assigned a value of 1.0.