One-phase Flow in Pipelines

The state of flow of a fluid in a pipeline is described by the Reynolds number Re (Equation 2.4-8)  

M = flow velocity d = pipe diameter V = kinematic viscosity. 

The amount of fluid exiting a pipe with cross-sectional area A = n/4 cf is given by Equation (2.4-10), which is used for the determination of dynamic viscosity with a Ubbelohde viscosimeter  

The other limiting case, so-called plug flow, occurs above about Re = 10 000 and is characterized by  

In the transition region (2300 Pe 10 000) a labile flow profile is found that, depending on the roughness of the pipe, can oscillate between these boundary values. For the formation of a constant flow profile, a certain distance I is required, which can be estimated with Equation (2.4-12)  

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