adiabaatiline

Adiabaatiline refers to a thermodynamic process where no heat is exchanged between a system and its surroundings. In an adiabatic process, the system is isolated in such a way that energy transfer as heat is prevented. This can be achieved by using insulating materials or by performing the process very rapidly, so that there is insufficient time for significant heat transfer to occur.

During an adiabatic expansion, a gas does work on its surroundings, and because no heat is added to the system, its internal energy decreases, leading to a drop in temperature. Conversely, during an adiabatic compression, work is done on the system, increasing its internal energy and thus its temperature.

Adiabatic processes are fundamental to understanding many natural phenomena and engineering applications. For instance, the cooling of air as it rises in the atmosphere is approximated as an adiabatic process, which contributes to cloud formation. In internal combustion engines, the compression and expansion strokes are often treated as adiabatic. The rapid compression of gases in a diesel engine raises their temperature sufficiently to ignite the fuel without the need for a spark plug. The concept is also crucial in the study of thermodynamics, where it helps to define ideal cycles like the Carnot cycle.