Question

Define volume flow rate Q of air flowing in a duct of area A with average velocity V

Answer 1

Answer:

The volume flow rate of air is $Q=A\times V$

Explanation:

A random duct is shown in the below attached figure

The volume flow rate is defined as the volume of fluid that passes a section in unit amount of time

Now by definition of velocity we can see that 'v' m/s means that in 1 second the flow occupies a length of 'v' meters

From the attached figure we can see that

The volume of the prism that the flow occupies in 1 second equals

$Volume=Area\times V=A\times V$

Hence the volume flow rate is $Q=V\times A$