| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1861180 | Physics Letters A | 2015 | 5 Pages |
•New energy dissipation law is verified for unsteady spatially periodic turbulence.•New energy flux law for high Reynolds number unsteady turbulence is discovered.•These laws hold both in forced and decaying turbulence.
Direct Numerical Simulations of unsteady spatially periodic turbulence with time-dependent rms velocity u′(t)u′(t) and integral length-scale L(t)L(t) show that not only the instantaneous energy dissipation rate but also the instantaneous energy flux at intermediate wavenumbers scales as U0L0u′(t)2/L(t)2 where U0U0 and L0L0 are velocity and length scales characterizing initial or overall unsteady turbulence conditions. These high Reynolds number scalings are qualitatively different from the well-known u′(t)3/L(t)u′(t)3/L(t) cornerstone scalings of equilibrium turbulence where the energy flux and dissipation are exactly balanced at all times.
