OpenFOAM is primarily designed to solve problems in continuum mechanics, i.e. the
branch of mechanics concerned with the stresses in solids, liquids and gases and
the deformation or flow of these materials. OpenFOAM is therefore based in 3
dimensional space and time and deals with physical entities described by tensors.
The coordinate system used by OpenFOAM is the right-handed rectangular Cartesian
axes as shown in Figure 1.1. This system of axes is constructed by defining an
origin from which three lines are drawn at right angles to each other, termed
the , , axes. A right-handed set of axes is defined such that to an
observer looking down the axis (with nearest them), the arc from a
point on the axis to a point on the axis is in a clockwise sense.
from which three lines are drawn at right angles to each other, termed
the 
, 
, 
axes. A right-handed set of axes is defined such that to an
observer looking down the 
axis (with 
nearest them), the arc from a
point on the 
axis to a point on the 
axis is in a clockwise sense.
