Page 93 - ebook fluid mechanics_finalize

FLUID MECHANICS

Example 4.11

A Inclined venturi meter (Figure 4.11) measures the flow of oil of specific gravity 0.82 and

has an entrance of 125 mm diameter and throat of 50 mm diameter. There are pressure
gauges at the entrance and at the throat, which is 300 mm above the entrance. If the

2
coefficient for the meter is 0.97 and pressure difference is 27.5 kN/m , calculate the actual
3
discharge in m /s.

Solution to Example 4.11

2

1

z1 z2

Figure 4.11 : Inclined Venturi Meter

In equation (2),

C  A   p − p   
Q actual = d 1  2g  1 2  + (z 1 − z 2 )  
(m 2 − ) 1      

This is independent of z1 and z2, so that the gauge reading x for a given rate of

flow, Qactual does not depend on the inclination of the meter.

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