Ansys Polyflow automatically integrates the total volumetric flow rate along all boundary sets, so you do not need to define a postprocessor sub-task for Flow Rate. Results are displayed as numerical values in the Ansys Polyflow listing file (search for the word Flow rates to find them).

This mass balance is a measure of the quality of the solution, and is defined as the ratio of the total flow rate along all boundary sets to the maximum inlet flow rate.