modelPrescribed1
Example - Isobaric process
Extends from Modelica.Icons.Example (Icon for runnable examples).
Information
This example illustrates several variants of using the Isobaric process for heat transfer defined by time varying inputs (outlet state and mass flow rate given).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| SI.AbsolutePressure | p_inf | 100000 | Ambient pressure |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| SI.MassFlowRate | m_flow | massFlowRate.y | Mass flow rate |
| Medium.AbsolutePressure | p | inletPressure.y | Pressure (inlet = outlet) |
| Medium.Temperature | T_in | inletTemperature.y | Inlet temperature |
| SI.TemperatureDifference | dT | temperatureDifference.y | Temperature difference |
| Medium.Temperature | T_out | T_in + dT | Outlet temperature |
| Medium.ThermodynamicState | state_in | Medium.setState_pTX(p, T_in, Medium.X_default) | Inlet state |
| Medium.ThermodynamicState | state_out | Medium.setState_pTX(p, T_out, Medium.X_default) | Outlet state |
| Medium.SpecificEnthalpy | h_in | Medium.specificEnthalpy(state_in) | Inlet specific enthalpy |
| Medium.SpecificEnthalpy | h_out | Medium.specificEnthalpy(state_out) | Outlet specific enthalpy |
| Medium.SpecificEnthalpy | dh | h_out - h_in | Specific enthalpy difference |
| Medium.SpecificEnergy | q | dh | Specific heat flow rate |
| SI.HeatFlowRate | Q_flow | m_flow*q | Heat flow rate |
| Medium.Density | rho_in | Medium.density(state_in) | Inlet density |
| Medium.Density | rho_out | Medium.density(state_in) | Outlet density |
| SI.SpecificVolume | v_in | 1/rho_in | Inlet density |
| SI.SpecificVolume | v_out | 1/rho_out | Outlet density |
| Medium.SpecificEnergy | u_in | h_in - p/rho_in | Inlet specific internal energy |
| Medium.SpecificEnergy | u_out | h_out - p/rho_out | Outlet specific internal energy |
| Medium.SpecificEnergy | du | u_out - u_in | Specific internal energy difference |
| SI.SpecificEnergy | w_exp | -p*(v_out - v_in) | Specific expansion work |
| SI.SpecificEnergy | w_amb | -p_inf*(v_out - v_in) | Specific ambient pressure work |
| SI.SpecificEnergy | w_exp_net | w_exp - w_amb | Net specific expansion work |
| SI.Power | P | m_flow*w_exp_net | Net power (net expansion work flow rate) |
| ThermofluidStream.DropOfCommons | dropOfCommons | ||
| Modelica.Blocks.Sources.SawTooth | inletPressure | ||
| Modelica.Blocks.Sources.SawTooth | inletTemperature | ||
| Modelica.Blocks.Sources.SawTooth | temperatureDifference | ||
| Modelica.Blocks.Sources.RealExpression | outletTemperature | ||
| Modelica.Blocks.Sources.SawTooth | massFlowRate | ||
| ThermofluidStream.Boundaries.Source | source | ||
| .ThermofluidStream.Boundaries.Sink_m | sink | ||
| ThermofluidStream.Idealized.Processes.Isobaric | dT1 | ||
| ThermofluidStream.Boundaries.Source | source1 | ||
| .ThermofluidStream.Boundaries.Sink_m | sink1 | ||
| ThermofluidStream.Idealized.Processes.Isobaric | T_out1 | ||
| ThermofluidStream.Boundaries.Source | source2 | ||
| .ThermofluidStream.Boundaries.Sink_m | sink2 | ||
| ThermofluidStream.Idealized.Processes.Isobaric | dh1 | ||
| ThermofluidStream.Boundaries.Source | source3 | ||
| .ThermofluidStream.Boundaries.Sink_m | sink3 | ||
| ThermofluidStream.Idealized.Processes.Isobaric | h_out1 | ||
| Modelica.Blocks.Sources.RealExpression | specificEnthalpyDifference | ||
| Modelica.Blocks.Sources.RealExpression | outletSpecificEnthalpy | ||
| ThermofluidStream.Boundaries.Source | source5 | ||
| ThermofluidStream.Idealized.Processes.Isobaric | dT2 | ||
| .ThermofluidStream.Boundaries.Sink_m | sink5 | ||
| ThermofluidStream.Boundaries.Source | source6 | ||
| ThermofluidStream.Idealized.Processes.Isobaric | T_out2 | ||
| .ThermofluidStream.Boundaries.Sink_m | sink6 | ||
| ThermofluidStream.Boundaries.Source | source7 | ||
| ThermofluidStream.Idealized.Processes.Isobaric | dh2 | ||
| .ThermofluidStream.Boundaries.Sink_m | sink7 | ||
| ThermofluidStream.Boundaries.Source | source8 | ||
| ThermofluidStream.Idealized.Processes.Isobaric | h_out2 | ||
| .ThermofluidStream.Boundaries.Sink_m | sink8 |
Contents
| Name | Description |
|---|---|
 Medium |
Revisions
-
2026, by Raphael Gebhart (raphael.gebhart@dlr.de):
Initial version.