A straight pipeline of internal diameter m carries oil of density kg m and dynamic…
PHYSICS · Multi-part · Fermi University Physics · Fluids & Continuum Physics · Viscous flow and dynamical similarity · Viscous flow and dynamical similarity
Fluids and Continuum Physics, Ch Dimensional analysis, dynamical similarity and the dimensionless groups
Problem
A straight pipeline of internal diameter Dp=0.60 m carries oil of density 880 kg m−3 and dynamic viscosity 0.040 Pa s at a mean speed of 1.5 m s−1. The flow is treated as steady and incompressible, and every pipe Reynolds number here is built on the internal diameter and the mean speed.
((a)) The pressure drop Δp along a length l of such a pipe is taken to depend on D, l, the mean speed U, the density ρ and the viscosity μ. How many independent dimensionless groups can be formed from these six quantities?
((b)) Compute the Reynolds number of the oil flow.
((c)) The pipeline is to be modelled by a geometrically similar pipe of internal diameter 0.050 m carrying water of density 1000 kg m−3 and dynamic viscosity 1.0×10−3 Pa s. What mean water speed gives the same Reynolds number?