Hydraulic Structures: Fourth Edition

Equations (9.19) and (9.20) suggest the maximum entrance loss at

the inlet:

∆he1.3V^2 /2g V^20 /2g. (9.21)

The rack losses,∆hr, can be expressed by (Fig. 9.20)

∆hr(s/b)4/3sin V^2 /2g(Kirschmer’s formula) (9.22)

(with flow parallel to rack bars), where is a coefficient which depends on

the type of rack bar (Table 9.2).

396 DIVERSION WORKS

Fig. 9.19 Guide vanes layouts upstream of intake for sediment exclusion

Fig. 9.20 Rack loss