I'm building a custom fluid model to eventually allow for a 3-dimensional velocity. I've designed the equations such that the model runs with the following boundary conditions:
pressure_out = 500000;
hin=3000e3;
mdot[1] = 66.3;
The inlet pressure, outlet enthalpy, and outlet mass flow rates should then all be calculated via the model. I then put in an outlet connector (standard Modelica fluid port named Outlet):
Outlet.m_flow + mdot[3]=0;
Outlet.p = pressure_out;
Outlet.h_outflow = hout;
and correspondingly remove the boundary condition for pressure_out so that:
hin=3000e3;
mdot[1] = 66.3;
and the model is still balanced. However, once I add in the Inlet connector and set its connections:
Inlet.m_flow =mdot[1];
Inlet.p = pressure_in;
Inlet.h_outflow = hin;
I remove the boundary conditions because the model should be capable of being informed of a pressure, mass flow rate, and enthalpy. However, when I remove my boundary conditions the model believes that I'm missing an equation. I cannot for the life of me figure out what to do. If I re-add in any of the initial boundary conditions, the model breaks because a boundary is singularly over-determined. In summary,
pout = 500000; replaced by Outlet.p = pout;
hout = states[2].h; add Outlet.h_outflow = hout;
p[1] = pin; add Inlet.p = pin;
hin=3000e3; replaced by Inlet.h_outflow = hin;
mdot[1] = 66.3; replaced by Inlet.m_flow = mdot[1];
I've tried using inStream for the flow variables, I've tried bypassing my internal variables, and I've tried each port one at a time. The Inlet port is unhappy, and I'm at a loss as far as why it is.