TKE
Turbulent kinetic energy, commonly abbreviated as TKE and denoted by k in many models, is a scalar quantity used to characterize the intensity of turbulence in a fluid flow. It represents the mean kinetic energy per unit mass associated with velocity fluctuations around a flow’s mean motion. In Reynolds decomposition, a velocity component is written as u = U + u', where U is the temporal or spatial mean and u' is the fluctuating part. The TKE is defined as k = 1/2 ⟨u'_i u'_i⟩, with summation over the three spatial directions and ⟨·⟩ denoting a time, ensemble, or spatial average.
Physical interpretation and budget: TKE is governed by a balance among production, dissipation, and transport. In
Measurement and modeling: In experiments, TKE is inferred from measurements of velocity fluctuations using hot-wire anemometry,
See also: turbulence, Reynolds-averaged Navier–Stokes equations, turbulence models.