Finite Volume Analysis:   Application of Conservation of Linear Momentum     

 

Example 3  (continued)

                          

                 

 

The equation for conservation of mass is:

 

                          ∂/∂t ∫ ρ dV  +  ∫ ρ V n  dS  =  0

                                cv             cs

 

For steady flow the first integral is zero.  The second integral becomes:

 

                       ρ V1n1 A1  +  ρ V2n2 A2  + ρ V3n3  A3  =  0

 

where  n1  =  ˗ i  ,  n2  =  cos θ i  + sin θ j ,   n3  =  ˗cos θ i  ˗ sin θ j

 

            V1  =  V1  i,    V2  =  V2 n2 ,  V3  =  V3 n3     and  V1 =  V2  =  V3  =  Vj  

 

where   Vj  =  the speed of the air  jet

 

So for conservation of mass: 

 

                             ˗ ρ Vj   A1  +  ρ Vj  A2  +  ρ Vj A3  =  0                                        (1)

 

 

The equation for conservation of linear momentum is:

   

                          ∂/∂t ∫ ρ V dV  +  V ρ V n  dS  =  F

                                cv             cs

 

 

Click here to continue with this example.

 

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