Dunkirk: Where History Happened. We visit 10 places connected with the remarkable evacuation of the British Expeditionary Force from northern France in 1940. This feature was first published in the April 2010 edition of BBC History Magazine. Tuesday 25th May 2010.
The seepage velocity is less than the actual flow rate of the liquid or gas in the pores because the fluid moves only through the portion of the cross-sectional area S that is occupied by the pores.
In physics and engineering, in particular fluid dynamics and hydrometry, the volumetric flow rate, (also known as volume flow rate, rate of fluid flow or volume velocity) is the volume of fluid which passes per unit time; usually represented by the symbol Q (sometimes VÌ). The SI unit is m3/s (cubic metres per second).