Nomenclature

This page should serve as a guide to all the mathematical and physical symbols found in this documentation.

Physical symbols

Symbol	Meaning
\(T\)	Temperature [K]
\(\lambda\)	Heat conductivity [W m\(^{-1}\) K\(^{-1}\)]
\(\rho\)	Density [kg m\(^{-3}\)]
\(c\)	Specific heat capacity [J kg\(^{-1}\) K\(^{-1}\)]
\(\Delta t\)	The time step size [s]
\(\Delta x\)	The size of the volume around a discretized spatial point [m]
\(\delta x\)	The distance between two discretized spacial points [m]
\(Q_{\text{sol}}\)	The incoming solar power per area, usually time and angle dependent [W m\(^{-2}\)]
\(Q_{\text{refl}}\)	The fraction of power per area gained by a surface through absorption of reflected light from surrounding geometry [W m\(^{-2}\)]
\(Q_{\text{refl, total}}\)	The fraction of power per area gained by a surface through absorption of reflected light from surrounding geometry, altered for an incident angle dependent albedo case [W m\(^{-2}\)]
\(Q_{\text{refl}}\)	The fraction of power per area gained by a surface through absorption of infrared thermal emission from surrounding geometry [W m\(^{-2}\)]
\(\epsilon\)	Emissivity
\(\sigma\)	Stefan-Boltzmann constant [W m\(^{-2}\) K\(^{-4}\)]
\(\alpha\)	Bond albedo
\(\boldsymbol{x}\)	A coordinate vector of a point - in the context of facets the centroid
\(F(\boldsymbol{x}_i \boldsymbol{x}_j)\)	Viewfactor between facets
\(\boldsymbol{F}_{ij}\) or \(\boldsymbol{F}(\boldsymbol{x}_i \boldsymbol{x}_j)\)	Viewfactor matrix whose entries are the viewfactors scaled by the areas of the facets

Common abbreviations and namings

Abbreviation/Name	Meaning
TPM	Thermophysical model
GMRES	Generalized Minimum Residual Method
TDMA or Thomas-Algorithm	Tridiagonal Matrix Algorithm
Facet	A polygonal surface element (most commonly a triangel or rectangle) of a bigger surface
Mesh	A collection of facets that describe a bigger surface, often containing information like vertices, facets, areas of facet, etc.
Tri/Tris	Shortform for Triangular polygon/trigon