In the thermal domain, all the ports are fluid ports.Unlike 'terminal' in DME, a port is independent of a component.
It is a combination of a 'joint' and a 'terminal'.
the area of the cross section of the port
the elevation of the port with respect to some reference point
(Forall (?Self ?Time)
(<=> (Active ?Time Port ?Self)
(And (Port ?Self)
(Active ?Time Thermal-Component ?Self))))
(=> (Port ?Self)
(And (Quantity.Dimension (Port-Area ?Self) Area-Dimension)
(Quantity.Dimension (Port-Elevation ?Self) Length-Dimension)))