Eric, two answers.

The short answer: run

and after that you can see the algebraic variables and system equations.

The slightly longer answer: When you run a simulation with WSMLink (WSMSimulate["model"]) the model is translated by SystemModeler into the binary and that's what you run, the simulation results are then read back into Mathematica. You will always get the same results as running a simulation in SystemModeler Simulation Center. When you run WSMModelData["model"] WSMLink will convert the Modelica equations into Wolfram Language.

There are some constructs in Modelica that there are no representations for in the Wolfram Language, so it will not always be possible to fully translate everything.

It should work regardless of domain. Unfortunately there was a bug in WSMLink (the Mathematica package for SystemModeler) that slipped into the release.

It has been fixed and should work in the next version.

Hi!

I now see the problem you are having. This seems to be an issue in WSMLink with the Thermal.FluidHeatFlow library that you are using in your model, where something is not currently supported. I've been told that this is something that will be addressed in an upcoming version.

Hi again Eric!

When I try and validate your model in SystemModeler it tells me that it is structurally singular, maybe that's whats causing your problems?

[6] 22:48 Validation of model EricsTraining.SplitJunction
Error: [:0:0-0:0] Error: Model is structurally singular, the equations
volumeFlow.constantVolumeFlow = 0.0;
do not allow to solve for required variables.