From “Lost Work” to “Entropy Production”: Examining the Cost to the Surroundings in Irreversible Isothermal Processes of Ideal Gases

Abstract This paper utilizes LabVIEW software to develop a simulation program for reversible and irreversible isothermal processes of an ideal gas. By varying the number of steps N, a process chain from irreversible to nearly reversible is implemented. The simulation results are used to re-examine the cost to the surroundings in reversible/irreversible processes. Thermodynamic concepts such as work, heat, entropy, and the second law of thermodynamics are integrated into teaching, providing a new pedagogical approach for reversible/irreversible processes. The rationale follows five steps to examine the cost to the surroundings in irreversible processes: Comparing work → Utilizing functions → Selecting the metric → Understanding the Principle → Finding the Relationship. The greater the irreversibility of the process (smaller N), the higher the cost to the surroundings, as reflected in the greater amount of energy dissipated (larger entropy production ΔST and larger lost work Wlost). Linear regression is employed to verify the strict applicability of Wlost = TΔST in ideal gas isothermal processes, and the quantitative relationship between the thermodynamic loss (Wlost, ΔST) and the degree of irreversibility (number of steps N) is obtained. The total score distribution of the postclass exercises was concentrated without any large range. Questionnaire survey results indicate that students hold highly positive attitudes toward the software’s practicality, ease of use, and effectiveness, with balanced performance across all three dimensions and no apparent weaknesses.