On Illustrating Carnot’s General Proposition by Means of Reversible Stirling Engines

Carnot’s general proposition, also referred to as one of Carnot’s principles, states that the work producing potential of heat—harvested by reversible heat engines—is independent on the working fluid and on engine internal details, being only a function of the temperatures of the reservoirs with which the engine exchanges heat. This concept, usually presented to ME students in the context of the second law of thermodynamics, is usually proven by contradiction, using second law concepts and abstractions, without concrete examples, even though Carnot’s proposition mentions concrete things such as working fluids and engine internal details. This work proposes to document the usage of reversible Stirling engine models that take the engine arrangement and fluid properties into account towards illustrating the validity of Carnot’s general proposition.