Chapt06

# It is better to define f with respect to the head

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Unformatted text preview: n from the outer wall. We omit such a scheme here and proceed directly to the friction factor. According to the general rule proposed in Eq. (6.89), turbulent friction is predicted with excellent accuracy by replacing d in the Moody chart | e-Text Main Menu | Textbook Table of Contents | Study Guide 364 Chapter 6 Viscous Flow in Ducts by Deff 2(a b)/ , with values listed in Table 6.3.6 This idea includes roughness also (replace /d in the chart by /Deff). For a quick design number with about 10 percent accuracy, one can simply use the hydraulic diameter Dh 2(a b). Table 6.3 Laminar Friction Factors for a Concentric Annulus f ReDh 0.0 0.00001 0.0001 0.001 0.01 0.05 0.1 0.2 0.4 0.6 0.8 1.0 Deff/Dh 64.0 70.09 71.78 74.68 80.11 86.27 89.37 92.35 94.71 95.59 95.92 96.0 1/ 1.000 0.913 0.892 0.857 0.799 0.742 0.716 0.693 0.676 0.670 0.667 0.667 EXAMPLE 6.14 What should the reservoir level h be to maintain a flow of 0.01 m3/s through the commercial steel annulus 30 m long shown in Fig. E6.14? Neglect entrance...
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## This note was uploaded on 10/27/2009 for the course MAE 101a taught by Professor Sakar during the Spring '08 term at UCSD.

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