What happens to the total internal energy of a closed system during an adiabatic process?

During an adiabatic process, the total internal energy of a closed system remains constant if the system does not perform work, such as in an ideal gas undergoing an adiabatic free expansion. However, in a more general sense, an adiabatic process typically involves exchanges of work and may lead to changes in internal energy due to work being done on or by the system.

In an adiabatic system, no heat is exchanged with the surroundings. Thus, the only way to change the internal energy is through work. If work is done on the system (compression), the internal energy increases because energy is added to the system. Conversely, if the system does work on its surroundings (expansion), the internal energy decreases as energy is taken out. Therefore, if one assumes that the internal energy remains constant in a controlled scenario without any work being done and no heat transfer occurs, then it can be understood that certain processes might lead to a constant internal energy overall.

However, it's important to note that in actual adiabatic processes involving work, there is typically a change in internal energy, but the question appears to focus on a specific scenario where no external work is done. In such a controlled perspective, one could deduce that under certain