Integrating this quantity around a boundary gives the boundary's cyclic constant.
Integrating this quantity around a boundary gives the boundary's cyclic constant. A universal profile for this value, or the "law of the wall," says that it varies like the log of the distance from the wall plus a constant. The vortex shedding frequency equals this quantity times the Strouhal number over characteristic length. Drag depends linearly on this quantity in laminar but not turbulent flow. This quantity is equal to the square root of 2 g h by (*) Torricelli's theorem. This quantity's divergence is zero for incompressible flows and its curl is zero for irrotational flows. A decrease in pressure leads to an increase in this quantity according to Bernoulli's law. For 10 points, name this quantity which measures how fast a fluid is moving. 
Integrating this quantity around a boundary gives the boundary's cyclic constant.
flow velocity [or velocity field] 