Enumeration to define the formulation of balance equations (to be selected via choices menu):
Dynamics. | Meaning |
---|---|
DynamicFreeInitial | Dynamic balance, Initial guess value |
FixedInitial | Dynamic balance, Initial value fixed |
SteadyStateInitial | Dynamic balance, Steady state initial with guess value |
SteadyState | Steady state balance, Initial guess value |
The enumeration "Dynamics" is used for the mass, energy and momentum balance equations respectively. The exact meaning for the three balance equations is stated in the following tables:
Mass balance | ||
Dynamics. | Balance equation | Initial condition |
DynamicFreeInitial | no restrictions | no initial conditions |
FixedInitial | no restrictions | if Medium.singleState then no initial condition else p=p_start |
SteadyStateInitial | no restrictions | if Medium.singleState then no initial condition else der(p)=0 |
SteadyState | der(m)=0 | no initial conditions |
Energy balance | ||
Dynamics. | Balance equation | Initial condition |
DynamicFreeInitial | no restrictions | no initial conditions |
FixedInitial | no restrictions | T=T_start or h=h_start |
SteadyStateInitial | no restrictions | der(T)=0 or der(h)=0 |
SteadyState | der(U)=0 | no initial conditions |
Momentum balance | ||
Dynamics. | Balance equation | Initial condition |
DynamicFreeInitial | no restrictions | no initial conditions |
FixedInitial | no restrictions | m_flow = m_flow_start |
SteadyStateInitial | no restrictions | der(m_flow)=0 |
SteadyState | der(m_flow)=0 | no initial conditions |
In the tables above, the equations are given for one-substance fluids. For multiple-substance fluids and for trace substances, equivalent equations hold.
Medium.singleState is a medium property and defines whether the medium is only described by one state (+ the mass fractions in case of a multi-substance fluid). In such a case one initial condition less must be provided. For example, incompressible media have Medium.singleState = true.
type LinePattern = enumeration(Dash, DashDot, DashDotDot, Default, Dot, None, Solid);