Meshing in cfd
Family I · Instruments
Not to be confused with cfd, cfd trading, cfd analysis.
Meshing in CFD is the construction of a computational grid that subdivides the region of interest into discrete control volumes or elements. The mesh defines where and how the Navier–Stokes equations are approximated, so its density, shape and distribution determine both the accuracy and the cost of a simulation. A mesh is not a trading instrument; it is a numerical artefact used in engineering analysis.
What a mesh contains
A mesh is a collection of nodes, edges, faces and cells. In three dimensions the cells are typically tetrahedra, hexahedra, prisms or pyramids. Each cell carries the local values of velocity, pressure, temperature and other transported quantities.
- Structured mesh: cells arranged in a regular index space (i, j, k).
- Unstructured mesh: arbitrary connectivity, common around complex geometry.
- Hybrid mesh: structured layers near walls combined with an unstructured core.
Mesh quality is judged by skewness, aspect ratio, orthogonality and smoothness of size change. Poor quality increases discretisation error and can prevent convergence.
Worked example: cell count and wall spacing
For a turbulent channel-flow simulation, the near-wall spacing is set from a target dimensionless wall distance y+.
If the channel half-height is 0.05 m and 30 cells are used across it with geometric stretching, the total cell count follows from the streamwise and spanwise resolution.
Mesh independence
A solution is considered mesh-independent when further refinement changes the quantities of interest by less than a stated tolerance. This is established by running the same case on successively finer meshes and comparing integral results such as drag, pressure drop or heat transfer rate. The acceptable tolerance varies by application and by the governing standards of the project.
Often confused with
- cfd
- A CFD is a financial contract for difference between two parties settling the change in an asset price, whereas meshing in CFD is a numerical grid used to solve fluid-flow equations; the visible sign is whether the term refers to a tradable contract or to computational cells.
- cfd trading
- CFD trading is the activity of buying and selling contracts for difference, while meshing in CFD is a preprocessing step in engineering simulation; the visible sign is the presence of a position, margin or settlement rather than a mesh file.
- cfd analysis
- CFD analysis is the broader engineering study of fluid behaviour using computational methods, of which meshing in CFD is one component; the visible sign is that analysis covers the whole simulation workflow, whereas meshing covers only grid generation.