SUMMARY
A new type of thermodynamic machine was designed and prepared for testing to evaluate its capability in extracting mechanical energy from low enthalpy heat sources. The system was completed with a newly designed rotary piston compressor and expander to improve efficiency. A numerical model was set up using commercially available CFD code ANSYS Fluent to evaluate the performance of the compressor and to identify the fluid dynamic related loss sources. In attempt to increase computational efficiency 3D and 2D computations were compared to find the simplest model which provides sufficient information to capture the important heat transfer and fluid mechanical features.