Rouse Number

The Rouse Number calculator computes the Rouse Number as a function of the sediment fall velocity (w_s), the eddy viscosity to diffusivity constant (beta), and the shear velocity (u_*).

INSTRUCTIONS: Choose units and enter the following:

• (w_s) This is the sediment fall velocity.
• (β) This is the constant that correlates the eddy viscosity to eddy diffusivity
• (κ) This is the von Kármán constant.
• (u_*)  This is the shear velocity.

Rouse Number (P): The calculator returns the Rouse Number.

The Math / Science

The Rouse Number is a non-dimensional number in fluid dynamics which is used to define a concentration profile of suspended sediment and which also determines how sediment will be transported in a flowing fluid.  The formula for the Rouse Number is:

P=w_s/(β•κ•u_*)

where:

• P is the Rouse Number
• w_s is the sediment fall velocity
• β is the constant which correlates eddy viscosity to eddy diffusivity
• κ is the von Kármán constant
• u_* is the shear velocity

References

Wikipedia (https://en.wikipedia.org/wiki/Rouse_number)