.BuildingSystems.Fluid.BaseClasses.PartialThreeWayResistance

Information

Partial model for flow resistances with three ports such as a flow mixer/splitter or a three way valve.

If energyDynamics ≠ Modelica.Fluid.Types.Dynamics.SteadyState, then at the junction of the three flows, a mixing volume will be present. This will introduce a dynamic energy and momentum balance, which often breaks algebraic loops. The time constant of the mixing volume is determined by the parameter tau.

Revisions

• March 7, 2022, by Michael Wetter:
  Set final massDynamics=energyDynamics.
  This is for #1542.
• March 22, 2020, by Filip Jorissen:
  Corrected error message of asserts that verify whether flow reversal occurs when verifyFlowReversal=true and portFlowDirection<>Bidirectional. See #1327.
• July 7, 2018, by Filip Jorissen:
  Added asserts that verify whether flow reversal occurs when verifyFlowReversal=true and portFlowDirection<>Bidirectional. See #963.
• July 8, 2018, by Filip Jorissen:
  Added nominal value of h_outflow in FluidPorts. See #977.
• March 30, 2018, by Filip Jorissen:
  Added graphical illustrations for the values of portFlowDirection. Added asserts that verify the consistency of the values of portFlowDirection. See #902.
• February 22, 2016, by Michael Wetter:
  Conditionally removed control volume vol, and added the conditional connnector port_internal. This was already done when the parameter dynamicBalance was present, but was updated wrong when this parameter was removed. Without these conditional components, the regression test for BuildingSystems.Fluid.Examples.ResistanceVolumeFlowReversal fails to simulate.
• December 17, 2015, by Michael Wetter:
  Added assignment redeclare final package Medium=Medium as this is required for OpenModelica. This is for https://github.com/lbl-srg/modelica-buildings/issues/475.
• February 20, 2016, by Ruben Baetens:
  Removal of dynamicBalance as parameter for massDynamics and energyDynamics.
• April 13 2015, by Filip Jorissen:
  Exposed options for flow reversal to users and added corresponding implementation.
• March 23 2010, by Michael Wetter:
  Changed start values from system.p_start or (code T_start) to Medium.p_default.
• September 18, 2008 by Michael Wetter:
  Replaced splitter model with a fluid port since the splitter model in Modelica.Fluid 1.0 beta does not transport mC_flow.
• June 11, 2008 by Michael Wetter:
  First implementation.