Regardless of the type of engine to be analyzed, you - as the user -
have to provide the volumes the working gas occupies in the different
subspaces of the engine, all in cm³ (1 in³ = 16.387064 cm³).
This is straight forward for the heater, regenerator, and cooler section as
these volumes are constant and only a single value is needed to describe them.
For the compression and the expansion space we need two values each.
As the expansion
space is identical for all engine types we start here. As the expansion piston
moves between its two extreme position the surface facing the working gas
sweeps out a volume called the swept volume which is equal to the
between the largest and the smallest volume of the expansion space. The
smaller of these two volumes is called the clearance volume.
For beta- and gamma-type engines the term swept volume refers
to the volume change of the compression space due to the motion of the
compression piston only, as if the displacer remains at a fixed position.
---- Good luck ----