Search

In this work we present an interactive learning object (LO) developed to facilitate the teaching/learning process of heat engines. The LO focus on the following issues: (1) time evolution, (2) neighborhood interaction, (3) energy exchange, (4) control capacity. These focus are necessary to overcome some learning difficulties identified in classroom when approaching the subject thru the pressure volume diagrams (PxV diagrams). The LO simulates a heat engine projected to redistribute energy of three other subsystems: two heat reservoir of different temperatures and a reversible work source. The LO can be adjusted by the user in such a way that the heat engine operates any cycle, reversible or irreversible, composed of four stages. Each of these stages is defined by the type of interaction between the engine and the neighbor subsystems. In particular, the LO can simulate a heat engine which operates on a reversible Carnot cycle, either direct of reverse. The LO interface presents an animation that represents a working heat engine in operation among the three other subsystems. In a side panel, it is shown the PxV diagram of the engine's working substance. Just below the animation, the LO has another panel where it is plotted four curves given the energy variation in function of time of the engine's working substance and the three other subsystems. Thru the plots of these two panels, that are updated in synchrony with the animation's movement, the user can, for instance, identify where irreversible processes take place. The LO provides adjusts that can be used to tune an initial irreversible cycle until it become a Carnot cycle by the systematic reduction of its irreversibility or by the searching of the most thermodynamic efficient engine. The LO can be found as the following web pages: [ABSTRACT FROM AUTHOR]