Volume flow rate

Volume flow rate: The volume of fluid passing by a given point per unit time throughan area is called the volume flow rate, or simply flow rate. Q 

     

Q=dv/dt

Consider an ideal fluid flowing with velocity through a uniform flow tube of cross section A. If, as shown in Fig. 2.34, the shaded cylinder of fluid of length x and volume V flows past point P in time t,

     V= dx/dt    and   V= Ax

Then, the volume  flow rate or volume  flux is 

   Q= dv/dt = d(Ax)/dt

                   = Adx/dt 

                   = Av.

The SI unit for volume flow rate is the cubic metre per second (m/s) Another common unit accepted in SI is the litre per minute (L/min).

 An old non-Sl unit from FPS system still used is the cubic feet

per second (symbol, sec).

Mass flow rate : The mass of thaid passing by a given point per unit time through an area is called the mass flow rate, dildt.

Refer to Fig. 2.34Consider an ideal fluid of density flowing with velocity e through a undoof cross section A. If, as shown in Fig 2.34, the shaded cylinder of fluid ofy Blows past point in time t