modelPartialTank
Extends from ThermofluidStream.Utilities.DropOfCommonsPlus.
Information
This Volume is the parent class for Accumulator and Receiver models that separate the two phases and are able to output gas, liquid or two-phase medium, depending on its liquid level and the height of the outlet. Numerical stiffness is handled the same way as in the VolumeFlex.
To complete the partialTank, equations for total tank volume V, centreOfMass, staticHeadInlets and staticHeadOutlets needs to be provided. This separation is made to make it easy to implement arbitrary geometries. In this component, medium.p is interpreted as the pressure at the liquid surface.
Since there is no formula to compute density_derp_h for this volume, an upper bound has to be set in the parameter density_derp_h_set. Alternativeley the derivative can be taken from the media model for all the media that implement the corresponding formula by setting density_derp_h_from_media=true (default:false)
The fundamental idea of the model is based on work by Hans Ellstroem (https://www.researchgate.net/profile/Soeren-Steinkellner/publication/312590863_MODELLING_AND_SIMULATION_OF_FUEL_SYSTEMS_IN_MILITARY_AIRCRAFTS/links/5884927e4585150dde47b6aa/MODELLING-AND-SIMULATION-OF-FUEL-SYSTEMS-IN-MILITARY-AIRCRAFTS.pdf).
Beware: This is a new addition to the library. It may be subject to design reconsiderations in future versions.
considerInertance
The parameter considerInertance is currently not included in the model; see
Idealized.UsersGuide.InertanceNeglect.
enableFreeInlet
The parameter enableFreeInlet is currently not included in the model; see
PartialVolume.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Boolean | useHeatport | false | If true heatport is added |
| SI.Area | A | 1 | Contact area of volume with medium |
| SI.CoefficientOfHeatTransfer | U | 200 | Heat transfer coefficient to medium |
| Medium.AbsolutePressure | p_ref | 1e5 | Reference pressure of tank when volume is measured |
| SI.BulkModulus | K | 5e7 | Bulk modulus of tank (used also for stiffness modulation) |
| Initialization | |||
| Boolean | initialize_pressure | true | If true: initialize Pressure |
| Medium.AbsolutePressure | p_start | Medium.p_default | Initial Pressure |
| Boolean | initialize_energy | false | Initialize specific inner energy with temperature or specific enthalpy condition |
| Medium.Temperature | T_start | Medium.T_default | Initial Temperature |
| Boolean | use_hstart | false | True: specific enthalpy condition instead of Temperature |
| Medium.SpecificEnthalpy | h_start | Medium.h_default | Initial specific enthalpy |
| Boolean | initialize_Xi | false | If true: initialize mass fractions |
| Medium.MassFraction[Medium.nXi] | Xi_0 | Medium.X_default[1:Medium.nXi] | Initial mass fraction |
| Boolean | initialize_LiquidMass | true | If true: initialize with mass of the liquid medium component. Initialize_Xi must be false. |
| SI.Mass | M_liq_start | 0 | Initial mass of the liquid |
| Advanced | |||
| Utilities.Units.Inertance | L | dropOfCommons.L | Inertance at inlet and outlet |
| SI.MassFlowRate | m_flow_assert | -dropOfCommons.m_flow_reg | Assertion threshold for negative massflows |
| Boolean | usePreferredMediumStates | false | Use medium states instead of the ones differentiated in this component |
| SI.Length | outletTransition | 0.01 | Width of band for smooth transition between gas and liquid at outlet |
| Advanced › Damping | |||
| Real | k_volume_damping | dropOfCommons.k_volume_damping | Damping factor multiplicator |
| General › Geometry | |||
| SI.Length[3] | tankCenter | {0, 0, 0} | Position of the tank center |
| Integer | N_inlets | 2 | Number of inlets |
| Integer | M_outlets | 2 | Number of outlets |
| SI.Length[N_inlets,3] | inletPositions | {{0, 0, 0}, {0, 0, 0}} | Positions of all inlets |
| SI.Length[M_outlets,3] | outletPositions | {{0, 0, 0}, {0, 0, 0}} | Positions of all outlets |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Interfaces.Inlet[N_inlets] | inlet | ||
| Interfaces.Outlet[M_outlets] | outlet | ||
| Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a | heatPort | ||
| Medium.BaseProperties | medium | ||
| SI.Volume | V | ||
| SI.Volume | V_liquid | ||
| SI.Volume | V_ref | Volume of the tank at p_ref | |
| SI.Mass | M | V*medium.d | |
| SI.Mass[Medium.nXi] | MXi | M*medium.Xi | |
| SI.Energy | U_med | M*medium.u | |
| SI.HeatFlowRate | Q_flow | ||
| SI.Power | W_v | ||
| SI.Length[3] | centerOfMass | ||
| SI.Length[N_inlets] | staticHeadInlets | distance perpendicular to liquid surface, 0 if above surface | |
| SI.Length[M_outlets] | staticHeadOutlets | distance perpendicular to liquid surface, 0 if above surface | |
| SI.Pressure[N_inlets] | staticHeadInlets_Pa_relative | relative pressure to liquid surface, 0 if above surface | |
| SI.Pressure[M_outlets] | staticHeadOutlets_Pa_relative | relative pressure to liquid surface, 0 if above surface | |
| Real[3] | normAcc | Modelica.Math.Vectors.normalize(acceleration.a) |
Contents
| Name | Description |
|---|---|
| Medium | Medium model |
Revisions
Author: Ingela Lind, M Sc, Ph D, Technical Fellow,
Simulation and Thermal Analysis,
Vehicle Systems,
SAAB Aerosystems, 2024