Fundamental Definition
Volume flow rate is defined by the limit:
I.e., the flow of volume of fluid V through a surface per unit time t.
Since this is only the time derivative of volume, a scalar quantity, the volumetric flow rate is also a scalar quantity. The change in volume is the amount that flows after crossing the boundary for some time duration, not simply the initial amount of volume at the boundary minus the final amount at the boundary, since the change in volume flowing through the area would be zero for steady flow (which isn't the case, since an amount of volume has passed the boundary in the time duration).
Read more about this topic: Volumetric Flow Rate
Famous quotes containing the words fundamental and/or definition:
“I believe the declaration that “all men are created equal” is the great fundamental principle upon which our free institutions rest.”
—Abraham Lincoln (1809–1865)
“The physicians say, they are not materialists; but they are:MSpirit is matter reduced to an extreme thinness: O so thin!—But the definition of spiritual should be, that which is its own evidence. What notions do they attach to love! what to religion! One would not willingly pronounce these words in their hearing, and give them the occasion to profane them.”
—Ralph Waldo Emerson (1803–1882)