modelStaticHead
Extends from ThermofluidStream.Interfaces.SISOFlow (Base Model with basic flow eqautions for SISO).
Information
Implementation of static head in a pipe.
To specify the acceleration vector, please use the AccelerationBoundary component.
Default is pure graviation in the negative z-direction.
Energy is moved between potential energy in an acceleration field and internal energy (pressure).
The main assumption is that the density is constant for the pressure change along the pipe. That would be the case for non-compressible fluids and many gases at low Mach numbers. For more insight in this look into the difference between the simplified and generalised forms of the Bernoulli equation.
Note that it is only the position difference that influence the pressure difference, not the absolute positions. If the inlet pressure is not sufficient to overcome the acceleration field between the pipe ends the static head is less than the length given by the position difference in the acceleration direction.
Beware: This is a new addition to the library. It may be subject to design reconsiderations in future versions
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| String | instanceName (from DropOfCommonsPlus) | getInstanceName() | Instance name |
| Boolean | displayPositions | true | show positions in icon |
| Layout | |||
| Boolean | displayInstanceName (from DropOfCommonsPlus) | dropOfCommons.displayInstanceNames | = true, if instance name is displayed |
| Boolean | displayParameters (from DropOfCommonsPlus) | dropOfCommons.displayParameters | = true, if displaying parameters is enabled |
| Advanced | |||
| Boolean | considerInertance (from SISOFlow) | dropOfCommons.considerInertance | =true, if transient momentum (inertance) term is considered; disable only for advanced use |
| Utilities.Units.Inertance | L (from SISOFlow) | dropOfCommons.L | Inertance |
| StateSelect | m_flowStateSelect (from SISOFlow) | StateSelect.default | State selection for mass flow rate |
| Boolean | clip_p_out (from SISOFlow) | = false, if dr_corr=0 (correction of inertial pressure difference) | |
| Medium.AbsolutePressure | p_min (from SISOFlow) | dropOfCommons.p_min | Minimum steady-state output pressure |
| ThermofluidStream.Utilities.Units.Inertance | L_value | dropOfCommons.L | Inertance of pipe |
| Medium.Density | rho_min | dropOfCommons.rho_min | Minimal input density |
| Initialization › Mass flow rate | |||
| InitializationMethods | initM_flow (from SISOFlow) | ThermofluidStream.Utilities.Types.InitializationMethods.none | Initialization method for mass flow rate |
| SI.MassFlowRate | m_flow_0 (from SISOFlow) | 0 | Initial value for mass flow rate |
| Utilities.Units.MassFlowAcceleration | m_acceleration_0 (from SISOFlow) | 0 | Initial value for derivative of mass flow rate |
| Geometry | |||
| SI.Length[3] | fromPosition | Coordinates for the position the static head is computed from | |
| SI.Length[3] | toPosition | Coordinates for the position the static head is computed to | |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Inlet | inlet (from SISOFlow) | ||
| Outlet | outlet (from SISOFlow) |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| SI.MassFlowRate | m_flow (from SISOFlow) | inlet.m_flow | Mass flow rate |
| SI.Pressure | dr_corr (from SISOFlow) | Correction of inertial pressure difference | |
| SI.Pressure | dp (from SISOFlow) | Pressure difference | |
| Medium.AbsolutePressure | p_in (from SISOFlow) | Medium.pressure(inlet.state) | Inlet pressure |
| Medium.SpecificEnthalpy | h_in (from SISOFlow) | Medium.specificEnthalpy(inlet.state) | Inlet specific enthalpy |
| Medium.MassFraction[Medium.nXi] | Xi_in (from SISOFlow) | Medium.massFraction(inlet.state) | Inlet mass fractions |
| Medium.AbsolutePressure | p_out (from SISOFlow) | Outlet pressure | |
| Medium.SpecificEnthalpy | h_out (from SISOFlow) | Outlet specific enthalpy | |
| Medium.MassFraction[Medium.nXi] | Xi_out (from SISOFlow) | Outlet mass fractions | |
| SI.Length | staticHead | static head in m | |
| SI.Pressure | staticHead_Pa_relative | static head measured i Pa, taking current acceleration and limitations into account |
Revisions
Author: Ingela Lind, M Sc, Ph D, Technical Fellow,
Simulation and Thermal Analysis,
Vehicle Systems,
SAAB Aerosystems, 2024