Energy Analysis of Closed Systems

Flashcards covering key concepts from the energy analysis of closed systems in thermodynamics.

Conservation of energy principle

The first law of thermodynamics which states that energy can neither be created nor destroyed, only changed from one form to another.

Energy balance

An equation that accounts for the energy entering and leaving a system, equating it to the change in energy within the system.

Unit-mass basis

An energy balance expressed per unit mass of the system.

Adiabatic process

A thermodynamic process in which no heat is transferred to or from the system.

Isochoric process

A thermodynamic process that occurs at constant volume.

Isothermal process

A thermodynamic process that occurs at constant temperature.

Isobaric process

A thermodynamic process that occurs at constant pressure.

Specific heat

The amount of heat required to raise the temperature of a unit mass of a substance by one degree.

Boundary work

Work associated with the movement of the boundary of a system, typically seen in processes involving pistons.

Kinetic energy (KE)

The energy possessed by a body due to its motion.

Potential energy (PE)

The energy possessed by a body due to its position or configuration.

Internal energy (U)

The total energy contained within a system, including kinetic and potential energy of molecules.

Cyclic process

A thermodynamic process that returns a system to its original state.

Mechanical work

Work done by forces acting at a distance, such as moving a piston.

Heat transfer (Q)

Energy transfer due to temperature difference between the system and its surroundings.

Energy conservation principle

Total energy before a process equals total energy after the process, summarizing the first law of thermodynamics.

Rate-form energy balance

An energy balance expressed in terms of energy per unit time.

Moving boundary work

Work done by or on the boundary of a system during expansion or compression.

Thermodynamic analysis

The study of energy transformations and the laws governing energy interactions.

Enthalpy (h)

A property of a system that accounts for internal energy and the energy required to make room for it by displacing its surroundings.

Energy interactions

Transfers of energy into or out of a system through work, heat, and mass flow.