mobile-phase speed

symbol: $u$
https://doi.org/10.1351/goldbook.10036
Linear velocity of the mobile phase across the average cross-section of the column.
Source:
PAC, 2017, 90, 181. 'Terminology of separation methods (IUPAC Recommendations 2017)' on page 196 (https://doi.org/10.1515/pac-2017-0111)