{"id":353151,"date":"2024-02-22T14:45:42","date_gmt":"2024-02-22T14:45:42","guid":{"rendered":"\/forum\/forums\/topic\/total-pressure-output-at-an-interior-bc-associated-with-a-fixed-value-fluid-zone\/"},"modified":"2024-02-22T14:45:42","modified_gmt":"2024-02-22T14:45:42","slug":"total-pressure-output-at-an-interior-bc-associated-with-a-fixed-value-fluid-zone","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/total-pressure-output-at-an-interior-bc-associated-with-a-fixed-value-fluid-zone\/","title":{"rendered":"Total Pressure output at an interior BC associated with a Fixed Value Fluid Zone"},"content":{"rendered":"

The example below is a simplied Fluent model of a larger complex system I have. I use a fixed value fluid zone to drive the system flow with inlet & outlet pressure BCs, default air properties and viscuous model. I have found that the face averaged total pressure output (Fluent, results, surface intergals, area-averaged<\/em>) at the Interior faces<\/span> does not sum to the static and dynamic pressures for the same faces. At the pressure inlet and outlet BC, it sums as it should. The error appears to be related to hydrostatic pressures but the results are unchanged by the presence or not of gravity. Is unaffected by mesh density. Is also incorrect using mass-average outputs. I have run for excessive iterations. This only happens when using a fixed value fluid zone. Removing the fixed value setting and changing the inlet BC to velocity, Ptot output at the same interior faces does sum to the static and dynamic pressures. <\/p>\n\n\n\n\n\n\n\n<\/colgroup>\n\n\n\n\n\n\n\n\n\n
 <\/td>\nArea Average<\/td>\nArea Average<\/td>\nArea Average<\/td>\nCalculated<\/td>\nDifference between <\/span><\/td>\n<\/tr>\n
 <\/td>\nPstat<\/sub><\/span><\/td>\nPdyn<\/sub><\/span><\/td>\nPtot<\/sub><\/span><\/td>\nPtot<\/sub><\/span>=P<\/span>stat<\/sub><\/span>+P<\/span>dyn<\/sub><\/span><\/td>\nPtot<\/sub><\/span> Output & Calculated<\/span><\/td>\n<\/tr>\n
——————————–<\/td>\n——————–<\/td>\n——————–<\/td>\n——————–<\/td>\n——————–<\/td>\n——————–<\/td>\n<\/tr>\n
 <\/td>\n[Pa]<\/td>\n[Pa]<\/td>\n[Pa]<\/td>\n[Pa]<\/td>\n[Pa]<\/td>\n<\/tr>\n
bc_inlet<\/td>\n-2.45<\/td>\n2.45<\/td>\n0.00<\/td>\n0.00<\/td>\n0.0<\/td>\n<\/tr>\n
bc_interior#1<\/td>\n-2.71<\/td>\n2.45<\/td>\n1.09<\/td>\n-0.26<\/td>\n1.4<\/td>\n<\/tr>\n
bc_interior#2<\/td>\n0.30<\/td>\n2.44<\/td>\n2.60<\/td>\n2.75<\/td>\n-0.2<\/td>\n<\/tr>\n
bc_outlet<\/td>\n0.00<\/td>\n2.47<\/td>\n2.47<\/td>\n2.47<\/td>\n0.0<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

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