modelVelocity
Extends from BuildingSystems.Fluid.Sensors.BaseClasses.PartialDynamicFlowSensor, Modelica.Icons.RoundSensor.
Information
This model outputs the flow velocity flowing from
port_a to port_b.
The sensor is ideal, i.e., it does not influence the fluid.
If the parameter tau is non-zero, then the measured
density that is used to convert the mass flow rate into
volumetric flow rate is computed using a first order differential equation.
Setting tau=0 is not recommend. See
BuildingSystems.Fluid.Sensors.UsersGuide for an explanation.
Typical use and important parameters
In order to use the flow velocity sensor, the cross sectional area of the flow
channel crossSection must be specified in m2. For a
circular flow channel (e.g. a round pipe) of diameter diameter, the
cross sectional area can be specified as crossSection = diameter *
diameter / 4 * Modelica.Constants.pi. See
BuildingSystems.Fluid.Sensors.Examples.Velocity for an example implementation
with diameter = 0.1.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Units.SI.Area | A | Cross sectional area of flow channel | |
| Initialization | |||
| Medium.Density | d_start | Medium.density(Medium.setState_pTX(p_start, T_start, X_start)) | Initial or guess value of density |
| Modelica.Units.SI.Temperature | T_start | Medium.T_default | Temperature used to compute d_start |
| Modelica.Units.SI.Pressure | p_start | Medium.p_default | Pressure used to compute d_start |
| Modelica.Units.SI.MassFraction[Medium.nX] | X_start | Medium.X_default | Mass fraction used to compute d_start |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Units.SI.VolumeFlowRate | V_flow | Volume flow rate from port_a to port_b | |
| Modelica.Blocks.Interfaces.RealOutput | v | Flow velocity from port_a to port_b |
Revisions
-
February 25, 2020, by Michael Wetter:
Changed icon to display its operating state.
This is for #1294. -
May 20, 2016, by Marcus Fuchs:
First implementation. Implementation is based on BuildingSystems.Fluid.Sensors.VolumeFlowRate.