Determining the flow losses through a pipe with friction

[Johan85]

Hi everyone,

I am trying to determine the flow losses through a pipe with friction. I understand that the Mach number increases through the pipe to unity and that the flow cannot increase when unity is reached. If the pipe is longer than the hypothetical chocking length, what would be the best way to quantify the frictional losses after chocking is reached?

Thank you so much in advance, I am very rusty when it comes to compressible flow.

 

[Travis_King]

Is this academic or practical? I.e. how precise of a measurement are you looking for. Pipes have different friction factors, and it is quite easy to estimate the friction losses based on capacity and pipe ID. Tons of literature and tables available for that. If it is an academic study, I'm sorry but I can't answer that right now as that is more involved than I would like to get into haha.

 

[Johan85]

Travis_King,

Thanks for the reply. I am actually quite confident with the surface roughness used to determine the friction factor, since I determined that empirically. I just want to know what flow model is used after the flow reaches mach 1 when using the Fanno flow model.

Regards