modelQuadratic_FlowFunction

Quadratic | Area and Kd/zeta definition | choked flow | compressible

Extends from ClaRa.Components.VolumesValvesFittings.Valves.Fundamentals.GenericPressureLoss.

Information

For detailed model documentation please consult the html-documentation shipped with ClaRa.

 


Authorship and Copyright Statement for original (initial) Contribution

Author:

DYNCAP/DYNSTART development team, Copyright © 2011-2024.

References:

For references please consult the html-documentation shipped with ClaRa.

Remarks:

This component was developed by ClaRa development team under the 3-clause BSD License.

Acknowledgements:

ClaRa originated from the collaborative research projects DYNCAP and DYNSTART. Both research projects were supported by the German Federal Ministry for Economic Affairs and Energy (FKZ 03ET2009 and FKZ 03ET7060).

CLA:

The author(s) have agreed to ClaRa CLA, version 1.0. See https://claralib.com/pdf/CLA.pdf

By agreeing to ClaRa CLA, version 1.0 the author has granted the ClaRa development team a permanent right to use and modify his initial contribution as well as to publish it or its modified versions under the 3-clause BSD License.

The ClaRa development team consists of the following partners:

TLK-Thermo GmbH (Braunschweig, Germany)

XRG Simulation GmbH (Hamburg, Germany).

Parameters

TypeNameDefaultDescription
Real[:,:]CL_valve[0, 0; 1, 1]|Valve Characteristics|Effective apperture as function of valve position in p.u.
RealKvsA_cross*sqrt(2/zeta)*sqrt(1e5/1000)*3600|Valve Characteristics|Flow Coefficient at nominal opening (Delta_p_nom = 1e5 Pa, rho_nom=1000 kg/m^3(cold water))
Basics.Units.MassFlowRatem_flow_nomKvs/1000/3600|Valve Characteristics|Only for homotopy-based initialisation: Nominal mass flowrate at full aperture_
Basics.Units.PressureDelta_p_eps100|Expert Settings||Small pressure difference for linearisation around zero flow
Valve Characteristics
IntegervalveDefinition1How valve characteristic is defined
Basics.Units.AreaA_cross1Valve cross section
RealKd1Outflow number, reduction of maximum outflow due to non ideal behaviour of valve
Realzeta100Pressure Loss coefficient

Components

TypeNameDefaultDescription
BooleancheckValve (from GenericPressureLoss)
BooleanuseHomotopy (from GenericPressureLoss)
Basics.Units.MassFlowRatem_flow (from GenericPressureLoss)
RealflowIsChoked (from GenericPressureLoss)1 if flow is choked, 0 if not
RealPR_choked (from GenericPressureLoss)Pressure ratio at which choking occurs
ClaRa.Components.VolumesValvesFittings.Valves.Fundamentals.IComiCom
Realaperture_Effective apperture
Basics.Units.PressureDifferenceDelta_pPressure difference p_in - p_out
Modelica.Blocks.Tables.CombiTable1DvValveCharacteristics
Basics.Units.PressureDifferenceDelta_p_chokemax(iCom.p_in, iCom.p_out) - max(iCom.p_in, iCom.p_out)*(2/(gamma + 1))^(gamma/(max(1e-3, gamma) - 1))Critical pressure difference, always positive i.e. independent of flow direction

Revisions

For revisions please consult the html-documentation shipped with ClaRa.