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FLUID MECHANICS
4.2 VOLUME FLOW RATE AND MASS FLOW RATE
4.2.1 Discharge ( Volume Flow Rate)
The volume of liquid passing through a given cross-section in unit time is called the
discharge. It is measured in cubic meter per second, or similar units and denoted
by Q.
Q = A. v
3
, units m /s
Example 4.1
If the diameter d = 15 cm and the mean velocity, v = 3 m/s, calculate the actual discharge
in the pipe.
Solution to Example 4.1
Q = Av
d 2 ( 15.0 ) 2
= v = 3 0= . 053 m 3 s /
4 4
4.2.2 Mass Flow rate
The mass of fluid passing through a given cross section in unit time is called the
mass flow rate. It is measured in kilogram per second, or similar units and denoted
•
by m .
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