The Fanno model for turbulent compressible flow

The paper considers the derivation and properties of the Fanno model for ne arly unidirectional turbulent flow of gas in a tube. The model is relevant to many industrial processes. Approximate solutions are derived and numeric ally validated for evolving flows of initially small amplitude, and these s olutions reveal the prevalence of localized large-time behaviour, which is in contrast to inviscid acoustic theory. The properties of large-amplitude travelling waves are summarized, which are also surprising when compared to those of inviscid theory.