Quality Metrics

The available metrics for assessing the mesh quality are included in the table shown below. It summarizes in which mesh parts (surface, boundary layer, element transition, tetrahedra) each quality metric can be applied and whether it is available for 2D meshes. The metrcs listed are categorized based on their type as follows:

Element properties
General metrics (node-based, face/cell-based, edge-based)
Solver-specific metrics (Fluent, OpenFOAM)

The expression of each quality metric, as well as information about typical ranges and example sketches of distorted elements can be found by clicking on the X marks in the table or by navigating to the desired metric via the following pages:

Quality Metric	Surface (Walls)	Boundary Layer	Element Transition	Tetrahedra	2D Meshes
Element Properties
Face Area	X				X
Edge Length	X				X
Volume				X

General (Face/Cell-based)
Sliver				X
Aspect Ratio	X			X	X
Edge Length Ratio	X			X	X
Dihedral Angle				X
Skewness				X
Volume Ratio				X
Degree of Non-Planarity (Quad Faces)	X

General (Node-based)
Skewness		X
Normal Stretching		X
Centroid Offset	X	X	X	X	X
Volume Ratio			X
Area Ratio	X				X
Quad Distortion		X

General (Edge-based)
Area Ratio	X				X

Fluent
Orthogonal Quality	X				X
Equiangular Skewness				X	X
Equivolume Skewness				X
Equiarea Skewness					X

OpenFOAM
Aspect Ratio				X
Orthogonality				X
Skewness				X