Colorado Experiment Station 
22 
The results of the calibration of the V-notch flume show that 
the loss of head is small for the usual conditions of operation, and 
that for any discharge the loss in head increases as the depth de- 
creases. For convenience in determining the loss of head caused 
by the installation of the V-notch flume in a channel, the results 
are given in graphical form in Figure 11. To find the loss of head 
when the discharge and average depth are known, find the depth in 
the column on the left of the diagram, follow the horizontal line at 
u 
I 
FIGURE 11. — Curves Showing the Loss of Head in Feet in a V-Notch 
Venturi Flume for Different Depths and Discharges. 
this point until it intersects the given discharge curve, and then read 
the loss of head in feet at the bottom of the diagram directly beneath 
the intersection. 
The discharge diagram, Figure 19 was plotted from results 
computed from the formula ; 
2 
Where — discharge in second feet, 
C=0.930 + (4.07--1.4// ) (//. -0.05 // - 0.04)2 
a a a 
Fa “Upper head in feet, 
Hb =throat head in feet, 
H(i— (H^ — Hb)= difference in head in feet, 
e -2.7183. 
e 
0.362 
y 
