(^1)
n
where
n0.80 0.26mo1/2
and the transition length, L2.35(B 0 Bf)1.65moyo,yobeing the flow
depth in the canal, and moits side slope. The side slopes (m) along the
transition are given by
m
m
o
^1 ^1
L
x
1/2
.
Using the constant specific energy condition in the transition between
canal and flume the depth in the flume, yf, and depths (yx) along the trans-
ition length can be obtained. The energy balance between adjacent sec-
tions within the transition with expansion loss as 0.3(V^2 i V^2 i 1 )/2ggives the
bed elevations to be provided at successive sections so that the specific
energy remains constant throughout the transition. Worked example 10.2
provides detailed design calculations for an expanding transition based on
the Vittal and Chiranjeevi method.
WATER SURFACE PROFILE IN TRANSITION
The water surface in the transition may be assumed as two smooth para-
bolic curves (convex and concave) meeting tangentially. Referring to
Fig. 10.4, the following equations give such profiles in transitions:
inlet transition, y8.96 10 4 x^2 ;
outlet transition, y2.33 10 4 x^2.
1 x
L
x
LBx Bf
B 0 Bf424 CROSS-DRAINAGE AND DROP STRUCTURES
Fig. 10.4 Water surface profile in transition (inlet)