Glossary
The acronyms, explained once
Among engineers these acronyms travel without a gloss. In a commercial conversation they do not: each one states what it solves and what it does not.
- CFD Computational fluid dynamics
- Solves fluid motion by dividing the domain into cells. It gives velocity, pressure, mixing and transport; it does not track individual particles, which is what DEM is for.
- FEA Finite element analysis
- Solves stress, strain and vibration modes in a solid. The quality of the answer depends on how the joints are represented, not on the size of the global model.
- DEM Discrete element method
- Tracks particles one by one with their contacts. It needs calibration with site material: without angle of repose and discharge tests, the result is an animation.
- GCI Grid convergence index
- Estimates how much of the result still depends on cell size, comparing at least three meshes with systematic refinement. It is what turns a mesh study into a reportable figure.
- y+ Dimensionless wall distance
- Tells whether the first cell falls inside the boundary layer or skips it. The acceptable value depends on the turbulence model chosen, which is why both are declared together.
- Von Mises Von Mises equivalent stress
- Reduces a three-axis stress state to a single number comparable against the material yield. It is a criterion for ductile metals; it does not apply the same way to concrete or to defective welds.
- Residual Error left at each iteration
- Measures how far the solution is from satisfying the equations. A low residual does not guarantee the result is right: it guarantees the solver stopped moving.
- Viridis Perceptually uniform scale
- A colour scale where an equal difference in value looks like an equal difference in colour, and which survives print and colour vision deficiency. Cividis is its print equivalent.