FLUENT - What is the meaning of the "Net" result printed from Surface Integrals command?
When using the Surface Integrals command, FLUENT prints out the quantities in the console window: for example, the area-weighted average pressure on the "inlet' and "outlet" zones. When more than one surface is selected, FLUENT also prints a quantity labelled "Net". What is the meaning of the quantity labelled "Net"?
The "net" result is determined by applying the given operator (e.g., area average, mass average, etc.) to all of the chosen zones as if they were all one zone. For example, if you compute the area-weighted average of the static pressure for two zones (zone1 and zone2), you will get the following:
zone1 sum_over_zone1(face_area * static pressure) / total_area_zone1
zone2 sum_over_zone2(face_area * static pressure) / total_area_zone2
Net [sum_over_zone1(face_area * static pressure) +sum_over_zone2(face_area * static pressure)]
/( total_area_zone1 + total_area_zone2)
In some cases you may not want the "net" result, but instead only the results from the individual zones.