Machine-translated by Google. Questions are authored in English.
Top

Discussion

Which quantity is the divergence of the velocity field?

  • A.The circulation
  • B.The rate at which the shape of a fluid element is distorted without any change to its total area
  • C.The rate of areal expansion of a fluid element
  • D.The rate at which a fluid element rotates about a vertical axis as it travels along with the flow

Answer: C

Divergence measures the fractional rate of increase of the area of a horizontal fluid element, so positive divergence means the element is spreading out. Rotation is vorticity, circulation is the loop integral of velocity, and shape change at constant area is deformation. Together these four describe every way a fluid element can be affected by the local velocity gradient.

No comment is present. Be the first to comment.
Loading…

Post your comment

Please log in or register to post a comment.