Open
System Daemons: Open Steady or Open
Process Problems
HOME.
Daemons.
Systems.
Open
Does
the state of the system remain frozen in time?
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Description
Open
Steady
The snapshot of the system taken with a State Camera (see the Tutorial>Algorithm
page) does not change with time when a system is at steady
state. In other words, the global state remains frozen so
that the total mass, energy, and entropy of the system do not change
with time. The differential balance equations simplifies into algebraic
equations as the time derivative of all global properties goes to zero.
The bulk of open system problems involving devices such as nozzles, turbines,
pumps, compressors, diffusers, condensers, evaporators, etc., belong to
this category.
Open
Unsteady
Instantaneous
The system is unsteady if
the snapshot, i.e., the global state, changes with time. Most of the unsteady
problems, however, involves integral quantities rather than instantaneous
rates. There are no special daemons in TEST for the unsteady, instantaneous
problems.
Open
Process
If the open system is unsteady and goes from a clear begin-state to
a clear finish-state, the hallmark of any process,
it executes an open process.
Beside the b- and f-states
as found in a closed process, there must be an inlet or exit port, characterized
by the i-state or e-state
in an open process. Charging a propane cylinder is an example of an open
process.
Open System and Its Governing Balance Equations (No change from the parent page.)
