Can Kinematic Simulation predict Richardson’s regime?

Abstract

It has been argued in (Thomson and Devenish in J. Fluid Mech. 526: 277–302, 2005) that owing to the lack of sweeping of small scales by large scales in kinematic simulation, this latter technique cannot predict Richardson’s regime. Here, we argue that the discrepancies between papers from different authors on the ability of kinematic simulation to predict Richardson power law may be linked to the inertial subrange they have used. For small inertial subranges, KS is efficient and the significance of the sweeping can be ignored, as a result we limit the KS agreement with the Richardson scaling law t3 for inertial subranges kN/k1 ≤ 104. Above this value, the sweeping effect of the small scales by the large scales may need to be taken into consideration though we cannot yet conclude as to the reason for the KS departing from the prediction of Richardson’s locality assumption when kN/k1 ≥ 104.