Astrophysics (index)

Reynolds Decomposition

(mathematical separation of average and fluctuating parts of a quantity)

Reynolds Decomposition is a mathematical separation of a quantity (an evolving field) into its average and its fluctuating parts. For example:

u(x,y,z,t) = u(x,y,z) + u'(x,y,z,t)
  • u - a quantity: a function of x,y,z, and t
  • u overbar - time-averaged u
  • u' - fluctuating part of u

It is used to help deal with the Navier-Stokes Equations (NS Equations).

The fluctuating component has a non-linear component which is called the Reynolds Stress or Reynolds Stresses. It accounts for Turbulence.

(mathematics,fluid dynamics,field)