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Unformatted text preview: typP6.158 Water at 20°C flows in a long horizontal commercial-steel
6-cm-diameter pipe which contains a classical Herschel | e-Text Main Menu | Textbook Table of Contents | Study Guide 420 Chapter 6 Viscous Flow in Ducts Word Problems p W6.1 In fully developed straight-duct flow, the velocity profiles
do not change (why?), but the pressure drops along the pipe
axis. Thus there is pressure work done on the fluid. If, say,
the pipe is insulated from heat loss, where does this energy
go? Make a thermodynamic analysis of the pipe flow.
W6.2 From the Moody chart (Fig. 6.13), rough surfaces, such as
sand grains or ragged machining, do not affect laminar flow.
Can you explain why? They do affect turbulent flow. Can
you develop, or suggest, an analytical-physical model of turbulent flow near a rough surface which might be used to
predict the known increase in pressure drop?
W6.3 Differentiation of the laminar pipe-flow solution, Eq. (6.40),
shows that the fluid shear stress (r) varies...
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- Spring '08