# Reynolds_number

plasmapy.formulary.dimensionless.Reynolds_number(rho: Unit('kg / m3'), U: Unit('m / s'), L: Unit('m'), mu: Unit('kg / (m s)'))

Compute the Reynolds number.

The Reynolds number is a dimensionless quantity that is used to predict flow patterns in fluids. The Reynolds number is defined as the ratio of inertial forces to viscous forces. A low Reynolds number describes smooth, laminar flow while a high Reynolds number describes rough, turbulent flow.

$Re = \frac{ρ U L}{μ}$

Aliases: Re_

Parameters
Warns

UnitsWarning – If units are not provided, SI units are assumed.

Raises

Examples

>>> import astropy.units as u
>>> rho = 1000 * u.kg / u.m ** 3
>>> U = 10 * u.m / u.s
>>> L = 1 * u.m
>>> mu = 8.9e-4 * u.kg / (u.m * u.s)
>>> Reynolds_number(rho, U, L, mu)
<Quantity 11235955.05617978>
>>> rho = 1490 * u.kg / u.m ** 3
>>> U = 0.1 * u.m / u.s
>>> L = 0.05 * u.m
>>> mu = 10 * u.kg / (u.m * u.s)
>>> Reynolds_number(rho, U, L, mu)
<Quantity 0.745>

Returns

Re – Dimensionless quantity.

Return type

Quantity