modelPressureIndependent
Test model for the pressure independent damper model
Extends from Modelica.Icons.Example (Icon for runnable examples).
Information
This model validates AixLib.Fluid.Actuators.Dampers.PressureIndependent by comparing it with
-
an exponential damper model which opening is the one computed by the
pressure independent model, see
damExp, -
an exponential damper model which opening is computed by a PI controller
tracking the same discharge mass flow rate, see
damExpPI.
The simulation consists in exposing these three models to
- a first increase in the pressure drop at the damper boundaries, from negative to positive values, with a zero input control signal,
- a consecutive increase of input control signal, from zero to one, with a constant pressure drop at the damper boundaries,
- an eventual decrease in the pressure drop, from positive to negative values, with an input control signal equal to one.
One can notice a small variation of the computed damper opening in the last transient around flow reversal. This is because the expression of the flow coefficient as a function of the mass flow rate and pressure drop is ill-defined near zero flow rate and the damper opening value results from the regularization process.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Units.SI.PressureDifference | dp_nominal | 10 | Damper nominal pressure drop |
| Modelica.Units.SI.MassFlowRate | m_flow_nominal | 1 | Damper nominal mass flow rate |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| AixLib.Fluid.Actuators.Dampers.Exponential | damExp | Damper with exponential opening characteristics | |
| Modelica.Blocks.Sources.Ramp | yRam | Ramp up damper control signal | |
| AixLib.Fluid.Sources.Boundary_pT | sou | Pressure boundary condition | |
| AixLib.Fluid.Sources.Boundary_pT | sin | Pressure boundary condition | |
| AixLib.Fluid.Actuators.Dampers.PressureIndependent | damPreInd | Pressure independent damper | |
| Exponential | damExpPI | Damper with exponential opening characteristics | |
| Controls.Continuous.LimPID | conPID | Discharge flow rate controller | |
| Sensors.MassFlowRate | senMasFlo | Discharge flow rate sensor | |
| Modelica.Blocks.Sources.Ramp | yRam1 | Ram up supply pressure | |
| Modelica.Blocks.Sources.Ramp | yRam2 | Ramp down supply pressure | |
| Modelica.Blocks.Math.Add | add | ||
| Sensors.RelativePressure | senRelPre | Pressure drop sensor | |
| Modelica.Blocks.Math.Gain | gain | Normalize discharge flow rate |
Contents
| Name | Description |
|---|---|
 Medium | Medium model for air |
Revisions
-
April 15, 2025, by Michael Wetter:
Changed initialization of controller.
For Buildings, #4183. -
April 5, 2020 by Antoine Gautier:
First implementation.