Integrate PressureLoss components from Dissipation library

[modelica-trac-importer]

Reported by kproelss on 28 Mar 2010 19:11 UTC
Pressure drop component models from the Dissipation library which make use of the library's collection of pressure drop correlations were decided to be integrated into Modelica.Fluid.Fittings release version 3.2 at the 66th Design Meeting, as complete top level component models.

The component models to be included need to fulfill the following requirements:

• A component model with an equivalent behavior must not exist among the already present components in Fluid.Fittings. Since MSL 3.2 will not be released with a conversion script. Non-backwards compatible changes such as removing such an obsolete component will not be permitted and are subject to a later release.
• All functions in Fluid.Dissipation, including those that are used in the component models, are called with two records as inputs. One contains the time-constant parameters, the other time-varying variables. At least the entire variable record needs to be set within the component model (such that the user does not need to set variable modifiers when using the component). It would be more convenient also to propagate all required parameter inputs to the component top level.
• As a component inside the Fittings package it actually has to belong to this category.

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Migrated-From: https://trac.modelica.org/Modelica/ticket/342

[modelica-trac-importer]

Comment by kproelss on 28 Mar 2010 20:19 UTC
In 23c4dba the packages Fittings.HeatTransfer and Fittings.PressureDrop have been removed. Component models available under Fluid.Fittings which use correlations from Fluid.Dissipation are now:

• Bends
  • Curved Bends
  • EdgedBend
• Orifices
  • ThickEdgedOrifice
  • SuddenChangeOrifice
• GenericResistances
  • NominalDensityViscosity
  • NominalVolumeFlowRate

They contain correlations for both possible unknowns (pressure drop and mass flow, respectively) and can therefore be used for both cases.

To do:

• The orifice models only describe dissipative losses and not change of static pressure due to a change in cross sectional area. Pressures in the ports are therefore total pressures, unlike existing Fluid library components.
• Input record parameters should be propagated to the component top level.

The following components were NOT included at this stage:

• Channel - special form of a pipe, should be a choice in that model
• General.IdealGas - The ideal gas constant is an input parameter, while actually being variable for gas mixtures.
• General.NominalPressureLossLawDensity - The pressure loss coefficient ZETA is a variable, needs to be handled in the user interface. More common: Parameterization with two parameter inputs, one for each flow direction.
• General.PressureLossCoefficient - same as above
• StraightPipe - all correlations, need to be integrated into existing pipe models.
• Valve - Opening is an input variable, should be propagated e.g. to signal port, valve components already exist in library.

For HeatTransfer components see #343.

[modelica-trac-importer]

Modified by otter on 16 Oct 2010 19:54 UTC

[modelica-trac-importer]

Comment by otter on 2 Jan 2013 21:59 UTC
It seems impossible to work on this ticket in the time frame for MSL 3.2.1, since a lot of work. Furthermore, these is an enhancement ticket and add (useful) functionality to the library.

Therefore, changed the milestone to "undecided

[modelica-trac-importer]

Changelog removed by otter on 2 Jan 2013 21:59 UTC