kvázistatikus

Kvázistatikus is a term used in physics and engineering to describe a process that occurs slowly enough to be considered as a sequence of equilibrium states. This means that at any point during the process, the system is essentially in equilibrium, or very close to it. This approximation is useful when analyzing systems that change over time but at a rate that is significantly slower than the internal relaxation times of the system.

In a truly static process, the system is not changing at all. In contrast, a quasistatic process involves a gradual change. The key characteristic is that the rate of change is so slow that any internal forces or gradients within the system have ample time to adjust and maintain a state of near-equilibrium. For example, in thermodynamics, a quasistatic compression of a gas would involve applying pressure so gradually that the gas molecules have time to redistribute and maintain uniform temperature and pressure throughout.

This concept is particularly relevant in areas such as thermodynamics, fluid mechanics, and solid mechanics. By treating a process as quasistatic, it becomes possible to apply equilibrium equations and relationships, simplifying complex analysis. However, it's important to remember that it is an approximation, and real-world processes are rarely perfectly quasistatic. The validity of the assumption depends on the specific system and the rate at which the external conditions are changed.