Talk:Diffuser (thermodynamics)

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I know a diffuser . Thank you

[edit] two definitions for diffuser?

Is it okay to think there're two definitions for diffuser?

One, probably more strict and precise one, is that "any duct designed to slow an incoming gas flow to lower velocity at the exit of the diffuser" (quoted from Fundamentals of Aerodynamics, 3rd ed., J. D. Anderson, Jr. (2001), p.577). Another is perhaps "any duct where its cross sectional area is increasing" or something like this.

They have the same divergent shape for subsonic flows, whereas for supersonic flows quite the opposite: any convergent duct is a diffuser for supersonic flows by the former difinition. Of course the inversed thing can be said for nozzle.

I'm saying this 'cos I was a bit confused while I was reading Expansion chamber#Transfer where it says "This part of the pipe is called the divergent (or diffuser) section". I have had the impression that the flow at the part usually becomes supersonic; if so the article uses the second definition... Or, merely the flow's subsonic? --Dynamicsoar 14:31, 9 November 2007 (UTC)