P (kpa) P c P Solid (i) i + f Liquid (f) f + g H 2 O i + g P t Vapor (g) T ( o C) T ( o C) P c CL SM SV v f v g CL compressed liquid SV superheated vapor SM saturated mixture v f saturated liquid curve v g saturated vapor curve P c critical point V (m 3 ) Saturated liquid: Liquid on the liquid-vapor curve in pressure-temperature space that would vaporize as a result of increase temperature or decrease in pressure.ģ Saturated vapor: Vapor on the liquid-vapor curve in pressure-temperature space that would condense as a result of decrease temperature or increase in pressure. Thermodynamic equilibrium: There is no apparent change in the number or mass of coexisting phases, and the properties do not vary from point to point in a system.Ģ Compressed liquid: The properties of the liquid are such that it would not vaporize as a result of small changes in temperature and/or pressure. Isothermal process: Processes that occur at constant temperature isobaric processes that occur at constant pressure isenthalpic processes that occur at constant enthalpy isentropic processes that occur at constant entropy (internally reversible, adiabatic). Irreversible processes: a process that is not reversible. Reversible processes: A process which, when reversed, leaves no effect on either the system or the surroundings.
Process: Series of successive states through which a system passes, expressed diagrammatically as a path. Specific properties: An extensive property divided by mass (specific volume V/kg = v) State Postulate: The state of a simple compressible pure substance is defined by two independent, intensive system properties Phase: A physically separable homogeneous quantity, such as a solid, liquid, or vapor that has the same composition throughout. Intensive properties: Properties independent of the size or extent of the system (temperature, pressure, density, specific volume, specific energy quantities) Extensive properties: Properties that depend on the size or extent of the system (mass, volume, various forms of energy). Properties can be related to each other through equations (equation of state), diagrammatically (property diagrams), or through tables (property tables). Property: A quantity used to describe a system. State: Condition of a system described by giving values to its properties at a given time. The concept of a boundary in thermodynamics is very important when considering heat and work, as both must cross a boundary. Boundary: Surface or interface between the system and surroundings, and may be real or imaginary does not have to be a physical barrier. Open system: Can exchange both energy and mass, and is often a fixed volume (control mass) Surroundings: Region outside the system or not included in the system. Closed system: Can exchange energy but not mass mass is constant (control mass. 1 FUNDAMENTALS OF ENGINEERING THERMODYNAMICS System: Quantity of matter (constant mass) or region in space (constant volume) chosen for study.