Quantification of nonlinear energy transfer rates in the transition of a plane wake to turbulence

The transition to turbulence of plane wakes is characterized by a sequence of instabilities and wave-wave interactions. As the instability modes grow, beyond the initial small-amplitude stage, the nonlinear terms of the governing equations become more important and could no longer be neglected. Their effect is to introduce nonlinear energy transfer between the spectral components. While, the consequences of these interactions, such as broadening of the power spectra, have been observed in many experiments, their characteristics have only been examined in limited cases. In this work, quantitative estimates of quadratic energy transfer rates between different spectral components at two downstream locations in a plane wake are presented.