Here is the theory behind each definition:
The area average of a quantity Phi is defined as:
whereas the ‘Bulk’ average of the same quantity phi is defined as:
These two averages are generally different. For example, for a pipe flow, the ratio between the bulk average and the area average of the velocity is 4/3 when the velocity profile is parabolic. For fully developed turbulent flow, the velocity profile has a plug shape and the ratio is close to 1, as shown in the picture below.
Thanks for the answer, that makes sense. Is there a spot on the Solidworks site where this information is available? I've had trouble finding definitions for some of the variables in Flow Simulation and haven't had much luck finding them in the training manual or software help menu.
3 choices: 1) check knowledge base with your profile and see if you can find an answer 2) ask your VAR 3) ask us here on the forum.