Nondimensionalization is the partial or full removal of
units from an
equation involving
physical quantities by a suitable substitution of
variables. This technique can simplify and
parameterize problems where
measured units are involved. It is closely related to
dimensional analysis. In some physical
systems, the term
scaling is used interchangeably with
nondimensionalization, in order to suggest that certain quantities are better measured relative to some appropriate unit. These units refer to quantities to the system, rather than units such as
SI units. Nondimensionalization is not the same as converting
extensive quantities in an equation to intensive quantities, since the latter procedure results in variables that still carry units.