Ok, as my torubles are not easily to understand without source code, I created a simple example, what is not working:

For the test I connected two boundaries from Modelica.Fluid.Sources:
MassFlowSource_T and Boundary_pT

If you are looking at the documentation of Boundary_pT, it says:
<p>If <code>use_p_in</code> is false (default option), the <code>p</code> parameter
is used as boundary pressure, and the <code>p_in</code> input connector is disabled; if <code>use_p_in</code> is true, then the <code>p</code> parameter is ignored, and the value provided by the input connector is used instead.</p>
<p>The same thing goes for the temperature, composition and trace substances.</p>

So I define m_flow, T and X fpr MassFlowSource_T and only the pressure for Boundary_pT:

model TestSingleMoistAir

  inner Modelica.Fluid.System system

    annotation (Placement(transformation(extent={{-76,68},{-56,88}})));



  Modelica.Fluid.Sources.MassFlowSource_T boundary_mT(

  

                                                      nPorts=1,

                                                      redeclare package Medium = Modelica.Media.Air.MoistAir,

                                                      m_flow=1000,

                                                      X={0.01,0.99},

                                                      T=353.15)

                                                      annotation (Placement(transformation(extent={{-66,20},{-46,40}})));

  Modelica.Fluid.Sources.Boundary_pT boundary_p(

                                                  nPorts=1,

                                                  redeclare package Medium = Modelica.Media.Air.MoistAir,

                                                  p=100000)

                                                  annotation (Placement(transformation(extent={{50,20},{30,40}})));                                                      

equation

  connect(boundary_mT.ports[1], boundary_p.ports[1]) annotation (Line(

      points={{-46,30},{30,30}},

      color={0,127,255},

      smooth=Smooth.None));

  annotation (Diagram(coordinateSystem(preserveAspectRatio=false, extent={{-100,

            -100},{100,100}}), graphics));

end TestSingleMoistAir;

When you do the simulation, you can see, that it does not what the documentation is promising:
It takes the default Temp in the bondary_pT and not the one from boundary_mT:

val(boundary_mT.ports[1].m_flow,1);

val(boundary_p.ports[1].m_flow,1);

val(boundary_mT.ports[1].h_outflow,1);

val(boundary_p.ports[1].h_outflow,1);

val(boundary_mT.medium.T,1);

val(boundary_p.medium.T,1)

Results in:
-1000.0
1000.0
106157.20683546351
45263.2387446934
353.15
293.15

=> Does anybody have an idea why this happens, and what I could do?
Thanks in advance.
Uwe

Hi,

This might be a bug either in the flattening (or in the back-end/runtime system).

I suggest you do instantiateModel and see what kind of equations you're getting.
Also, run omc from command line with +d=dumpindxdae and see how the variables are calculated (from which equation).
See here in the README how to write the script and give command line options:
https://build.openmodelica.org/omc/buil … ly-builds/

Let us know which version/revision of OpenModelica you're using (and what OS).

Cheers,
Adrian Pop/

Hi Adrian,
thank you for your reply.
I am using OpenModelica 1.9.0 beta4+dev (r16548) on WinXP Prof SP3, 32Bit.

I used the mos script and got a log file.
The temperature of the boundary seems to be calculated from the internal parameter which is by default 293.15K.
The equation in the log is:
"58/58 (1): boundary_p.medium.T = boundary_p.T_in_internal

But as referring to the help of the boundary_p object Modelica should ignore this value...

What else to do?
> I could send you my model and the log file.

Adrian, may I ask you for an advice to handle the usage of inStream an object  two streams entering and one stream leaving?

Regards,
Uwe