Non-dimensionalization and scaling of the Navier–Stokes equations
In fluid mechanics, non-dimensionalization of the Navier–Stokes equations is the conversion of the Navier–Stokes equation to a nondimensional form. This technique can ease the analysis of the problem at hand, and reduce the number of free parameters.
Source: Wikipedia — Non-dimensionalization and scaling of the Navier–Stokes equations (CC BY-SA 4.0)