Models an ideal flow source, with prescribed values of flow rate, temperature and composition:
If use_m_flow_in is false (default option), the m_flow parameter
is used as boundary pressure, and the m_flow_in input connector is disabled; if use_m_flow_in is true, then the m_flow parameter is ignored, and the value provided by the input connector is used instead.
The same thing goes for the temperature and composition
Note, that boundary temperature, mass fractions and trace substances have only an effect if the mass flow is from the boundary into the port. If mass is flowing from the port into the boundary, the boundary definitions, with exception of boundary flow rate, do not have an effect.