Limits to Energy Conversion

The Second Law of thermodynamics implies that no thermodynamic system with a single heat source at constant temperature can convert into mechanical work in recurrent manner. First, we note this is equivalent to cyclo-passivity the port system, while thermal kept constant. This leads question, which general systems two power ports have similar behavior: when cyclo-passive one its ports, output variable other (such as case) constant? property called “one-port cyclo-passivity,” and entails, whenever it holds, fundamental limitation energy transfer from other. Sufficient conditions for one-port are derived multiphysics formulated port-Hamiltonian form. illustrated by variety examples different (multi-)physical domains; coupled inductors capacitor microphones synchronous machines.