Flow rate

The flow rate (or flow velocity) is a physical size and defines the speed in a flow, in a directed movement of particles or in continuous bodies (liquids).
Flow velocity=(Volume flow )/(Area of pipe cross-section)

The flow rates of the individual particles are differentiated from the medium flow rate using a vector line element, a surface element, a volume element or a time interval. The flow rate is the spatial change of a single point along its trajectory. Medium flow rates can be determined for instance via the flow cross-section, the flow rate or a flow line. In literature, the flow rate is specified in a variety of ways. It is known under the symbols ω (small Omega), ν and c.
Alongside the viscosity the flow rate is an important factor influencing pressure loss and thus flows into the calculations for static mixers and heat exchangers.