next up previous index
Next: Isothermal Flow Up: Choking Flow Previous: Rayleigh Flow   Index


Fanno Flow

The most important model in compressible flow was suggested by Gino Fanno in his Master's thesis (1904). The model bears his name. Yet, according to Dr. Rudolf Mumenthaler from UTH University, no copy of the thesis can be found in the original University and perhaps only in the personal custody of the Fanno family1.41. Fanno attributes the main pressure reduction to friction. Thus, flow that is dominantly adiabatic could be simplified and analyzed. The friction factor is the main component in the analysis as Darcy $ f$ 1.42 had already proposed in 1845. The arrival of the Moody diagram, which built on Hunter Rouse's (194x) work made Darcy-Weisbach's equation universally useful. Without the existence of the friction factor data, the Fanno model wasn't able to produce a prediction useful for the industry. Additionally an understating of the supersonic branch of the flow was unknown (The idea of shock in tube was not raised at that time.). Shapiro organized all the material in a coherent way and made this model useful.

Meta

Did Fanno realize that the flow is choked? It appears at least in Stodola's book that choking was understood in 1927 and even earlier. The choking was assumed only to be in the subsonic flow. But because the actual Fanno's thesis is not available, the question cannot be answered yet. When was Gas Dynamics (compressible flow) as a separate class started? Did the explanation for the combination of diverging-converging nuzzle with tube for Fanno flow first appeared in Shapiro's book?

End Meta


next up previous index
Next: Isothermal Flow Up: Choking Flow Previous: Rayleigh Flow   Index
genick 2007-11-21