Physics:Power number

From HandWiki
For Newton number, see also Kissing number in the sphere packing problem.

The power number Np (also known as Newton number) is a commonly used dimensionless number relating the resistance force to the inertia force.

The power-number has different specifications according to the field of application. E.g., for stirrers the power number is defined as:[1]

[math]\displaystyle{ N_\mathrm{p} = \frac{P}{\rho n^{3} D^{5}} }[/math]



  1. Seinfeld, John H (1991). Wei, J; Anderson, J L; Bischoff, K B. eds. Advances in Chemical Engineering. Academic Press. p. 44. ISBN 978-0-08-056564-4.