modelSystemTF
Information
A system component is needed in each fluid model to provide system-wide settings, such as ambient conditions and overall modeling assumptions. The system settings are propagated to the fluid models using the inner/outer mechanism.
A model should never directly use system parameters. Instead a local parameter should be declared, which uses the global setting as default. The only exceptions are:
- the gravity system.g,
- the global system.eps_m_flow, which is used to define a local m_flow_small for the local m_flow_nominal:
m_flow_small = system.eps_m_flow*m_flow_nominal
The global system.m_flow_small and system.dp_small are classic parameters. They do not distinguish between laminar flow and regularization of zero flow. Absolute small values are error prone for models with local nominal values. Moreover dp_small can generally be obtained automatically. Consider using the new system.use_eps_Re = true (see Advanced tab).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Environment | |||
| Modelica.SIunits.AbsolutePressure | p_ambient | 101325 | Default ambient pressure |
| Modelica.SIunits.Temperature | T_ambient | 293.15 | Default ambient temperature |
| Modelica.SIunits.Acceleration | g | Modelica.Constants.g_n | Constant gravity acceleration |
| Advanced | |||
| Boolean | allowFlowReversal | true | = true to allow flow reversal, false restricts to design direction (port_a -> port_b) |
| Advanced › Dynamics | |||
| Dynamics | energyDynamics | Dynamics.DynamicFreeInitial | Formulation of energy balances |
| Dynamics | massDynamics | energyDynamics | Formulation of mass balances |
| Dynamics | substanceDynamics | massDynamics | Formulation of substance balances |
| Dynamics | traceDynamics | massDynamics | Formulation of trace substance balances |
| Dynamics | momentumDynamics | Dynamics.SteadyState | Formulation of momentum balances |
| Initialization › Start Value: Absolute Pressure | |||
| SI.AbsolutePressure | p_start | Medium.p_default | Pressure |
| Initialization › Start Value: Temperature | |||
| Boolean | use_T_start | true | Use T_start if true, otherwise h_start |
| SI.Temperature | T_start | Medium.T_default | Temperature |
| Initialization › Start Value: Specific Enthalpy | |||
| SI.SpecificEnthalpy | h_start | Medium.specificEnthalpy_pTX(p_start, T_start, X_start) | Specific enthalpy |
| Initialization › Start Value: Species Mass Fraction | |||
| SI.MassFraction[Medium.nX] | X_start | Medium.X_default | Mass fraction |
| Initialization › Start Value: Trace Substances | |||
| SIadd.ExtraProperty[Medium.nC] | C_start | fill(0, Medium.nC) | Mass-Specific value |
| Initialization › Start Value: Mass Flow Rate | |||
| SI.MassFlowRate | m_flow_start | 0 | Mass flow rate |
| Visualization | |||
| Boolean | showName | true | |
| Boolean | showDesignFlowDirection | true | |
| Visualization › Color Coding | |||
| Boolean | showColors | false | Toggle dynamic color display |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.SIunits.Acceleration | g_n | Modelica.Constants.g_n | Constant gravity acceleration |
| Real | val_min | 293.15 | val <= val_min is mapped to colorMap[1,:] |
| Real | val_max | 373.15 | val >= val_max is mapped to colorMap[end,:] |
Contents
| Name | Description |
|---|---|
 Medium |