Quasistatic equilibrium
Encyclopedia
Quasistatic equilibrium is the quasi-balanced state of a thermodynamic system
near to thermodynamic equilibrium
in some sense or degree. A process is called quasi-static
when it follows a succession of equilibrium states; the surroundings may be irreversibly altered during the process so that after a return path, the system ends up in a final state which differs from its initial state.
The quasistatic equilibrium model facilitates or justifies the use of Gibbsian thermodynamic applications, i.e. equations of state, to systems characterized by slow change if measured on the adjunct time scale. In short, the quasistatic equilibrium model approximates change as a series of equilibrium processes
.
In a quasistatic process, or equilibrium process, a sufficiently slow transition of a thermodynamic system from one equilibrium state to another occurs such that at every moment in time the state of the system is close to an equilibrium state. During a quasistatic process, the system reaches equilibrium much faster, almost instantaneously, than its physical parameters vary. A quasistatic process is not necessarily a reversible one.
For quasi-equilibrium, it is only required that the properties of the system be uniform at any instant during a process.
pdV-Work in Various Quasi-static Processes
(a)Constant pressure process (isobaric or isopiestic process)
W1-2=∫pdV=p(V2-v1)
(b)Constant volume process (isochoric process)
W1-2=∫pdV=0
(c)Process in which pV=C (isothermal process)
W1-2=∫pdV pV=p1V1=C
W1-2 = p1V1ln p1/p2
Thermodynamic system
A thermodynamic system is a precisely defined macroscopic region of the universe, often called a physical system, that is studied using the principles of thermodynamics....
near to thermodynamic equilibrium
Thermodynamic equilibrium
In thermodynamics, a thermodynamic system is said to be in thermodynamic equilibrium when it is in thermal equilibrium, mechanical equilibrium, radiative equilibrium, and chemical equilibrium. The word equilibrium means a state of balance...
in some sense or degree. A process is called quasi-static
Quasistatic process
In thermodynamics, a quasistatic process is a thermodynamic process that happens infinitely slowly. However, it is very important of note that no real process is quasistatic...
when it follows a succession of equilibrium states; the surroundings may be irreversibly altered during the process so that after a return path, the system ends up in a final state which differs from its initial state.
The quasistatic equilibrium model facilitates or justifies the use of Gibbsian thermodynamic applications, i.e. equations of state, to systems characterized by slow change if measured on the adjunct time scale. In short, the quasistatic equilibrium model approximates change as a series of equilibrium processes
Thermal equilibrium
Thermal equilibrium is a theoretical physical concept, used especially in theoretical texts, that means that all temperatures of interest are unchanging in time and uniform in space...
.
In a quasistatic process, or equilibrium process, a sufficiently slow transition of a thermodynamic system from one equilibrium state to another occurs such that at every moment in time the state of the system is close to an equilibrium state. During a quasistatic process, the system reaches equilibrium much faster, almost instantaneously, than its physical parameters vary. A quasistatic process is not necessarily a reversible one.
For quasi-equilibrium, it is only required that the properties of the system be uniform at any instant during a process.
pdV-Work in Various Quasi-static Processes
(a)Constant pressure process (isobaric or isopiestic process)
W1-2=∫pdV=p(V2-v1)
(b)Constant volume process (isochoric process)
W1-2=∫pdV=0
(c)Process in which pV=C (isothermal process)
W1-2=∫pdV pV=p1V1=C
W1-2 = p1V1ln p1/p2