[gschaider]

Originally Posted by aerogt3

I just download swak4foam, and right now I just want to get the average pressure and total mass flow rate at my velocity inlet, to compare with hand calcs and make sure I am using it correctly. To sum these, I am doing the following:

            mdot_inlet
            {
              type swakExpression;                                    
              valueType patch                                    
              patchName inlet      
              expression "phi*flip()";                                 
              accumulations
                (
                  sum                                                            
                );
              verbose true;
            }

            p_inlet
            {
              type swakExpression;                                    
              valueType patch;                                    
              patchName inlet      
              expression "p";                                 
              accumulations
                (
                  average                                                            
                );
              verbose true;
            }

I get the following error for averaging p, and I get the same error when performing the operation on faceZones.

[44] [24]
--> FOAM FATAL ERROR:
[42] --> FOAM FATAL ERROR: Could not find a field name "p" of type scalar (neither surfaceScalarField nor volScalarField) Autointerpolate: 0
[16]

And this one for mass flow rate. When I do mass flow rate calcs on faceZones, it works.

[42]
[42] --> FOAM FATAL ERROR:
[42] Parser Error at "1.5-8" :"field flip not existing or of wrong type"
"phi*flip()"
" ^^^^ "


Any ideas? As best I can tell, I am following your syntax correctly, no?

Average pressure should work ... if there is a field p. Which solver are you using

About flip(): you only need that on faceSets and faceZones. On patches the orientation of the faces is defined (all looking "in") and therefor flip() is not implemented for patches