Pipe-Line Construction: Dimensional Analysis & Pipe Roughness

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When designing a pipeline, selecting the appropriate pipe roughness is crucial, and dimensional analysis can help identify relevant parameters. Key variables include velocity (V), diameter (D), density (ρ), and viscosity (μ), which relate to the roughness of the pipe (ε). The discussion emphasizes the importance of the Reynolds Number in determining friction in pipes, which can be analyzed using graphs that correlate Reynolds Number, relative roughness, and friction factor. It is suggested that these are the primary parameters to consider for accurate calculations. Overall, understanding these relationships is essential for effective pipeline design.
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I'm designing a pipe-line and need to choose a specific value for pipe roughness. I'm trying to do dimensional analysis to find the needed pi groups.

That's what I did

ε (roughness of the pipe) = fcn(V,D, ρ μ)

V = Velocity

D = Diameter

ρ = density

μ = viscosity


Is there anything else I'm actually missing?
 
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If I recall correctly, friction in pipes has to do with the Reynolds Number (which is basically what you're going to find with those). There shouldn't really be any other parameters to consider. You can find graphs relating Reynolds #, relative roughness, and friction factor -- there are even some in my intro fluids book.

Does that answer your question?
 
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