Phase relations in a forced turbulent boundary layer: implications for modelling of high Reynolds number wall turbulence
Phase relations between specific scales in a turbulent boundary layer are studied here by highlighting the associated nonlinear scale interactions in the flow. This is achieved through an experimental technique that allows for targeted forcing of the flow through the use of a dynamic wall perturbation. Two distinct large-scale modes with well-defined spatial and temporal wavenumbers were simultaneously forced in the boundary layer, and the resulting nonlinear response from their direct interactions was isolated from the turbulence signal for the study. This approach advances the traditional studies of large- and small-scale interactions in wall turbulence by focusing on the direct interactions between scales with triadic wavenumber consistency. The results are discussed in the context of modelling high Reynolds number wall turbulence.
© 2017 The Author(s). Published by the Royal Society. Accepted October 14, 2016. This article is part of the themed issue 'Toward the development of high-fidelity models of wall turbulence at large Reynolds number'. The support of AFOSR under grant no. FA9550-12-1-0469 is gratefully acknowledged. Data accessibility: Experimental data associated with this study are available on request from the corresponding author. Authors' contributions: S.D. carried out the experiments and data analysis. S.D. and B.J.M. formulated the approach and the discussion. Both authors contributed to the manuscript and have approved it. We declare we have no competing interests.