.StreamConnectors.Interfaces.FluidPort

Information

The simples possible stream connector using

• mass flow rate as "flow" variable (in a connection point "flow" variables are automatically summed to zero like Kirchhoff's current law)
• pressure as "potential" (or "effort") variable (in a connection point the potentials are equal)
• specific enthalpy as "stream" variable (property carried with the direction of the flow)

Specific enthalpy vs. temperature

Why use specific enthalpy instead of temperature as stream variable when temperature seems more intuitive?

The answer is "automatic mixing equation": When you connect more than two stream connectors, the Modelica tool can automatically calculate the mixing enthalpy from knowledge of the flow directions, since m1*h1 + m2*h2 + ... + mN*hN = 0. This also means that it is not strictly necessary to create specific mixer/splitter components.

Why 'h_outflow'

Why is the enthalpy named h_outflow and not just h?

The reason is, that the variable is only relevant when the flow 'goes out' of the component to which the connector is attached.

Yes, really. If you want to know the value of the ingoing enthalpy after a simulation, you shold look at the value of h_outflow of the adjacent component (from which the mass flow 'goes out').

If a component needs to access the ingoing enthalpy it should use one of the functions inStream() or actualStream().