IEVref: 102-05-20 ID: Language: en Status: Standard Term: divergence Synonym1: Synonym2: Synonym3: Symbol: Definition: scalar div U associated at each point of a given space region with a vector U, equal to the limit of the flux of the vector which emerges from a closed surface S, divided by the volume of the interior of the surface when all its geometrical dimensions become infinitesimal $\mathrm{div}U=\underset{V\to 0}{\mathrm{lim}}\frac{1}{V}\underset{\text{S}}{∯}U\cdot {e}_{n}\mathrm{d}A$ where endA is the vector surface element oriented outwards and V is the volumeNote 1 to entry: In orthonormal Cartesian coordinates, the divergence is: $\mathrm{div}U=\frac{\partial {U}_{x}}{\partial x}+\frac{\partial {U}_{y}}{\partial y}+\frac{\partial {U}_{z}}{\partial z}$ Note 2 to entry: The divergence of the vector field U is denoted div U or ∇ ⋅ U. Publication date: 2017-07 Source: Replaces: 102-05-20:2007-08 Internal notes: CO remarks: TC/SC remarks: VT remarks: Domain1: Domain2: Domain3: Domain4: Domain5: