Stirling engine thermodynamics — Stirling cycle (isothermal expansion/compression, isochoric regeneration), ideal cycle efficiency (Carnot), Schmidt analysis (practical closed-form), regenerator effectiveness and NTU method, displacer/piston kinematics (alpha/beta/gamma configurations), dead volume penalty, power density, heat exchanger design (heater/cooler tubes), free-piston Stirling engines (FPSE), and applications in cryocoolers, solar dish Stirling, and CHP systems.