Page 109 - ebook fluid mechanics_finalize

FLUID MECHANICS

z1 = z2 because of the two parts are at the same level

We know that,

Q = A v

For continuity of flow, Q1 = Q2 or A1v1 = A2v2

A v
So, v2 = 1 1 ——————(3)
A 2

v 2 − v 2 p − p
Putting (3) into (2), 2 1 = 1 2 ——————(2)
2g 

A v
v2 = 1 1 ——————(3)
A 2

Then,

v  A 1 2 − 1 = p − p 2

2
1
1
2g   A 2 2  


So,

 p − p 
2g  1 2 
v =   
1 2
 A 
 1 −1 
 2 
 A 2 

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