Heat Engines

A heat engine is a device that converts thermal energy into mechanical work using temperature differences. In non-equilibrium thermodynamics, we study how these engines operate between hot and cold reservoirs, focusing on how energy flows and transforms when systems are not in balance. The engine absorbs heat from a high-temperature source, does work (like moving a piston), and releases some waste heat to a cooler environment. Efficiency depends on the temperature difference; the greater the difference, the more work can be produced. This principle underlies many technologies, from car engines to power plants.