OpenFOAM guide/Table of common fields

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.	$s^{-1}$