Finite Volume Analysis:       Selection of Control Surface or Surfaces

 

 

                             Control Surface and Control Volume

                   for Conservation of Energy for One Entry and One Exit

                                     from Control Surface

 

                           

 

where   CS  is the control surface        CV is the control volume

        P1, P2  are the pressures acting on the CS at 1 and 2  in lb/ft2 or N/m2

       V1, V2 are speeds of the fluid entering and exiting the control surface

                   in ft/sec or m/sec

        Z1, Z2  are the elevations at stations 1 and 2  in ft or m

              ρ  is the density of the fluid  in slugs/ft3  or  kg/m3

            hP  is the head added to the fluid by a pump in ft or m

            hT  is the head extracted from the fluid by a turbine in ft or m

            hL  is the head loss due to friction between stations 1 and 2 in ft or m

             g  is the acceleration of gravity in ft/sec2 or m/sec2 

 

       P1/ρg + V12/2g + z1 + hP  ˗ hT  =  P2/ρg + V22/2g + z2 + hL      (in ft or m)

 

    Energy In  +  Change in Energy  =  Energy out  +  Loss of Energy

 

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