OpenFOAM guide/Table of common fields

From OpenFOAMWiki

This table should give a list of the field names commonly written by the OpenFOAM-Solver.

It was inspired by the discussion What's the meaning of variables in the computed results in the Forum:

Fields written by OpenFOAM
Filename Description Dimension
U Velocity \frac{m}{s}
U_0 Velocity at previous timestep (needed for restarting higher order time-stepping schemes) \frac{m}{s}
phi Flow through cell faces. Depends on whether the solver is for incompressible or compressible flow. incompressible flow: \frac{m^3}{s}
compressible flow: \frac{kg}{s}
p Pressure. For incompressible solvers (example: simpleFoam), this field is actually the pressure normalized by constant fluid density. To get true pressure, you need to multiply by the density of your fluid in post processing. For compressible solvers, p is the true pressure. incompressible flow: \frac{m^2}{s^2}
compressible flow: \frac{kg}{ms^2}
epsilon Turbulence dissipation rate \frac{m^2}{s^3}
k Turbulence kinetic energy \frac{m^2}{s^2}
rho Gas density \frac{kg}{m^3}
alpha Dispersed phase volume fraction (Dimensionless, usually
within the interval [0, 1])
Theta Granular temperature \frac{m^2}{s^2}
rDeltaT The inverse of the timestep. For solvers that vary the local timestep (LTSInterFoam and similar) this indicates the local timestep. This can be especially useful for debugging. A high value of rDeltaT may indicate a need for further mesh refinement within a region. s^{-1}