Launch
an Open Process Daemon by Selecting a Material Model.
PC Model
The working substance is a phase-change (PC)
fluid. That is, it can exist as a sub-cooled liquid,
superheated
vapor, or as a mixture of saturated liquid and vapor. Example:
Saturated water vapor escaping a pressure cooker.
Gases:
PG Model
Obeys the ideal
gas equation
(pv=RT). Moreover, the specific heats
are assumed constant. A perfect gas (PG) is a simplified ideal gas. Example: Air enters an evacuated chamber.
IG Model
Obeys the ideal
gas equation
(pv=RT). Specific heats are temperature dependent; thus, the IG model is
more
accurate than the PG model. Example:
Air (variable specific heat) enters an evacuated chamber.
RG Model
Based on the generalized compressibility
chart (pv=ZRT), the real gas (RG) model can handle a large
number
of fluids with different phase compositions. But generality
comes
at the expense of accuracy. Example:
A propane tank is filled from a supply line. Note that use of the
PC
model will produce more accurate results.
Binary
Mixtures
The mixture contains two gases,
A and B, with its composition expressed
in terms of the mass or mole fraction of gas-A.
PG+PG
Model
IG+IG
Model
RG+RG
Model
General
Mixtures
Mixture can contain
any number of species
from 1 to n (n>60).
n-PG Model
n-IG Model
Open Process and Its Governing Balance Equations
System
Animation of an unsteady open system going through a process - a transition from a unique b-state to a unique f-state. The uniform-flow, uniform-state assumption used to simplify the analysis of an open process requires the anchor states to be uniform. For specific examples of open processes visit VT, section 5.E.
