[1] In the model, heat transferred through the walls of the conduit is offset by frictional heating back into the flow.
Although the flow temperature remains constant, a change in stagnation temperature occurs because of a change in velocity.
and not at Mach number equal to one as in the case of many other model such as Fanno flow.
For the important practical case of a gas flow through a long tube, the model has applicability in situations where distance is relatively long and heat transfer is relatively rapid so temperature can be treated, for engineering purposes, as a constant.
This model also has applicability as upper boundary to Fanno flow.