modelPressureIndependent
Model for an air damper whose mass flow is proportional to the input signal
Extends from IBPSA.Fluid.BaseClasses.PartialResistance, IBPSA.Fluid.Actuators.BaseClasses.ActuatorSignal.
Information
Model for an air damper whose airflow is proportional to the input signal, assuming
that at y = 1, m_flow = m_flow_nominal. This is unless the pressure difference
dp is too low,
in which case a kDam = m_flow_nominal/sqrt(dp_nominal) characteristic is used.
The model is similar to IBPSA.Fluid.Actuators.Valves.TwoWayPressureIndependent, except for adaptations for damper parameters. Please see that documentation for more information.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Boolean | use_deltaM | true | Set to true to use deltaM for turbulent transition, else ReC is used |
| Real | deltaM | 0.3 | Fraction of nominal mass flow rate where transition to turbulent occurs |
| Modelica.SIunits.Velocity | v_nominal | 1 | Nominal face velocity |
| Modelica.SIunits.Area | A | m_flow_nominal/rho_default/v_nominal | Face area |
| Boolean | roundDuct | false | Set to true for round duct, false for square cross section |
| Real | ReC | 4000 | Reynolds number where transition to turbulent starts |
| Advanced | |||
| Boolean | use_constant_density | true | Set to true to use constant density for flow friction |
| Real | l | 0.0001 | Damper leakage, l=kDam(y=0)/kDam(y=1) |
| Real | l2 | 0.01 | Gain for mass flow increase if pressure is above nominal pressure |
| Real | deltax | 0.02 | Transition interval for flow rate |
| Nominal condition | |||
| Modelica.SIunits.PressureDifference | dpFixed_nominal | 0 | Pressure drop of duct and other resistances that are in series |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Real | phi | l + y_actual*(1 - l) | Ratio actual to nominal mass flow rate of damper, phi=kDam(y)/kDam(y=1) |
| Medium.Density | rho | Medium density |
Revisions
-
March 21, 2017 by David Blum:
First implementation.