Large-scale spatio-temporal fluctuations in von Kármán turbulence

Abstract

Recent numerical studies of turbulence in a periodic cube showed that the well-known Taylor’s dissipation law does not hold. This implies the invalidity of the local equilibrium hypothesis, i.e., the instantaneous balance between the energy flux and energy dissipation in small scales. To demonstrate this phenomenon in a more realistic flow and to establish new dissipation scaling of turbulence, we investigate the von Kármán turbulent flow by direct numerical simulations using spectral element method (SEM) and experiments using particle image velocimetry (PIV) and laser doppler velocimetry (LDV).