1. n. [Production Logging]

The velocity of fluid moving through a pipe, defined as the volumetric flow rate of that fluid divided by the cross-sectional area. In monophasic flow, it is equal to the mean velocity of the fluid. In multiphase flow, it is not a physically real velocity but is a convenient parameter for analysis.

See: flow regime,  flow structure,  laminar flow,  multiphase flow,  turbulent flow