CONTINUITY EQUATION
Fluid Flow
So by using the continuity equation, we find that the increase in pipe diameter from 6 to 8 inches
m1
m2
r1 A1 v1
r2 A2 v2
v2
v1
r1
r2
A1
A2
v1
p r
2
1
p r
2
2
22.4
ft
sec
(3 in)2
(4 in)2
v2
12.6
ft
sec
caused a decrease in flow velocity from 22.4 to 12.6 ft/sec.
The continuity equation can also be used to show that a decrease in pipe diameter will cause an
increase in flow velocity.
Figure 3 Continuity Equation
HT-03
Page 12
Rev. 0
