The role of coherent structures and inhomogeneity in near-field interscale turbulent energy transfers
F. Alves Portela, G. Papadakis, J. C. Vassilicos
Abstract
We use direct numerical simulation data to study interscale and interspace energy exchanges in the near field of a turbulent wake of a square prism in terms of a Kármán–Howarth–Monin–Hill (KHMH) equation written for a triple decomposition of the velocity field which takes into account the presence of quasi-periodic vortex shedding coherent structures. Concentrating attention on the plane of the mean flow and on the geometric centreline, we calculate orientation averages of every term in the KHMH equation. The near field considered here ranges between two and eight times the width , and appears to correlate with the purely stochastic nonlinear interscale transfer rate when the orientation average is lifted.