Definitions for "INTERNAL ENERGY"
Ability of a working fluid to do its work based on the arrangement and motion of its molecules.
The sum of the kinetic and potential energies of the particles in a system. The internal energy of the system is proportional to its temperature.
(U, E) Compare with enthalpy and energy. Internal energy (U) is defined so that changes in internal energy ( U) are equal to the heat absorbed or released by a process running at constant volume. While changes in internal energy can be measured using calorimetry, absolute values of internal energy usually cannot be determined. Changes in internal energy are equal to the heat transferred plus the work done for any process.