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FLUID MECHANICS

Derivation for the theoretical discharge through a horizontal venturi meter and

modification to obtain the actual discharge.

From Figure 4.9

Putting;

p1 = pressure of section 1

v1 = velocity of section 1

A1 = area of section 1

p2 = pressure of section 2

v1 = velocity of section 1

A1 = area of section 1

ω1 = liquid in pipeline (specific weight)

ωg = liquid in the gauge (specific weight)

2
g = gravity (9.81 m/s )

z = height above datum

Bernoulli’s Equation for section 1 and 2 give:

v 2 p v 2 p
z + 1 + 1 = z + 2 + 2
1
2g  1 2g 

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