Flow rate of a tube

[hamed]

Dear Elmer
Is there any facility in Elmer to calculate the flow rate of a tube or nozzle?
Regards, Hamed

[raback]

Yes. You could use subroutine SaveScalars and there the Operator "convective flux" over given boundary.

-Peter

[hamed]

Hi Peter
Would you please give me the variables associated with convective flux? I mean

Code: Select all

Solver 4
  Procedure = "SaveData" "SaveScalars" 
  Filename = flux.dat
  Operator 1 = convective flux
  Variable 1 = ?
  Variable 2 = ?
  Variable 3 = ?
End

Regards, Hamed

[hamed]

Dear Elmer
I'll be extremely grateful if one can answer my previous question (the variables associated with convective flux).
Regards, Hamed

[raback]

Hi Hamed

Generally you would give the full vector (which for N-S is by default confusingly "Flow Solution"). The routine takes the DIM first components and computes \int c v \cdot n dA. The coefficient could be "Density'" to give mass flux. Without the coefficient it would just be volume flux. You can also integrate over one component (Velocity 1, for example) if in you geometry you know how your outlet is oriented.

Code: Select all

Solver 4
  Procedure = "SaveData" "SaveScalars" 
  Filename = flux.dat
  Operator 1 = convective flux
  Variable 1 = Flow Solution
  Coefficient 1 = Density
End

-Peter