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Unformatted text preview: s is based on velocity head in
the small pipe.
372 0 0.2 0.6 0.4 1.0 0.8 d
D | e-Text Main Menu | Textbook Table of Contents | Study Guide L
d 6.7 Minor Losses in Pipe Systems 373 fits the empirical formula
0.76, above which it merges into the sudden-expansion predicKSC 0.42 1 up to the value d/D
tion, Eq. (6.101).
If the expansion or contraction is gradual, the losses are quite different. Figure 6.23
shows the loss through a gradual conical expansion, usually called a diffuser . There
is a spread in the data, depending upon the boundary-layer conditions in the upstream
pipe. A thinner entrance boundary layer, like the entrance profile in Fig. 6.6, gives a
smaller loss. Since a diffuser is intendsed to raise the static pressure of the flow, diffuser data list the pressure-recovery coefficient of the flow
p2 Cp p1 1
2 (6.103) 2
V1 The loss coefficient is related to this parameter by
V /(2g) K 2 4
d2 1 Cp (6.104) For a given area ratio, the higher the pressure recovery, the lower the...
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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.
- Spring '08