Rouse number

The Rouse number is a non-dimensional number in fluid dynamics which determines how sediment will be transported in a flowing fluid. It is a ratio between the sediment fall velocity $w_{s}$ and the upwards velocity on the grain as a product of the von Kármán constant $\kappa$ and the shear velocity $u_{*}$.

${\textbf {Rouse}}={\frac {w_{s}}{\kappa u_{*}}}$

The required Rouse numbers for transport as bed load, suspended load, and wash load, are given below.

Mode of Transport	Rouse Number
Bed load	>2.5
Suspended load: 50% Suspended	>1.2, <2.5
Suspended load: 100% Suspended	>0.8, <1.2
Wash load	<0.8

See also

• Sediment transport
• Sediment
• Dimensionless quantity

References

• Whipple, K. X (2004), 12.163 Course Notes, MIT Open Courseware. http://ocw.mit.edu/NR/rdonlyres/Earth--Atmospheric--and-Planetary-Sciences/12-163Fall-2004/9D91F442-7769-4CAE-853E-213FCBD04081/0/3_flow_around_bends.pdf