# Roshko number

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Roshko number

In fluid mechanics, the Roshko number is a dimensionless number describing oscillating flow mechanisms. It is given as:

:$mathit\left\{Ro\right\} = \left\{St\right\} \left\{Re\right\} = \left\{f L^\left\{2\right\}over u\right\}$

where Ro is the dimensionless Roshko number, St is the dimensionless Strouhal number, Re is the Reynolds number, "f" is the frequency of vortex shedding, "L" is the characteristic length (for example hydraulic diameter) and "ν" is the kinematic viscosity of the fluid.

ee also

*Reynolds number
*Strouhal number

References

*Olim, A. M., Riethmuller, M. L., and Gameiro da Silva, M. C., 2002, "Flowfield characterization in the wake of a low-velocity heated sphere anemometer", "Exp. Fluids", 32, pp. 645-651.
*Ormieres, D., and Provansal, M., 1999, “Transition to turbulence in the wake of a sphere”, "Phys. Rev. Lett.", 83, pp. 80-83.

* [http://etd.caltech.edu/etd/available/etd-10302003-144124/ On the Development of Turbulent Wakes From Vortex Streets] PhD. Thesis by Anatol Roshko (hosted on Caltech Site).

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