Alpha Stirling engine interpretation

The following photos show the sequence of Alpha Stirling engine operation:

Notes:

1. In fact the two cylinders are not mechanically coupled using a belt (not practical) but I used belt here for explanation purpose.

2. The flame logo represents the heat source.

3. There is a heat regenerator in the passage connecting the two cylinders.

4. Not all Alpha Striling engines have the same configuration.

Rhombic drive mechanism

Rhombic drive is a mechanism used in piston-cylinder arrangements to reduce the lateral force of piston on the cylinder in order to reduce the friction force. The principle is: producing a lateral force equal in magnitude and has an opposite direction to the original lateral force in pure slider-cranck mechanism.

The following photo shows how the mechanism works:

Rotating mesh using Rigid Motion option in ADINA-CFD

The photo below shows you the rotating mesh capability of ADINA-CFD which can be used for axial turbomachines (as they move with constant rpm).

As you see, there are two element groups one in red and one in green. The green element group is the "rotating mesh" element group while the red one is the "stationary mesh" element group.

The two element groups are separated by a small gap (smaller gaps are preferred) and the interface between the two element groups is configured as a sliding mesh.

Note that the rotaing mesh has "Quadrilateral" elements and the stationary one is "Delaunay" triangulation.