# HyperMesh-Alt

HyperMesh CFD includes some alternate methods of calculating certain element types, which only apply to quads or rectangular faces of solids, and only include alternate checks for Aspect Ratio, Skew, Taper and Warpage.

Note: Because these methods apply only to certain quality checks, in order to use
them you must choose the set individually option in the
Check Element settings.

- Aspect Ratio
- ratio1 = V1/H1
- Skew
- First, HyperMesh CFD constructs lines connecting the midpoints of each edge of the quad, dotted in the picture below. Next, HyperMesh CFD constructs a third line, green in the picture below, perpendicular to one of the initial lines, then finds the angle between this third line and the remaining initial line – with which is it most likely not perpendicular, unless the quad is a perfect rectangle.
- Taper
- First, the quad’s nodes are projected to plane defined by the
orthonormal vectors U-V found as follows:
- Z = X × Y
- V = Z × X
- U = X

- Warpage
- Only applies to quads or rectangular faces of solids.Warpage = 100 * h / max { Li }, where h is the minimum distance between the diagonals.