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Accueil > Actualités > Séminaires > Séminaires 2019

Mardi 10 septembre 2019 à 11h00 en amphi K118

Tatsuya Yasuda, Nagoya Institute of Technology

Titre/Title : Spatio-temporal analysis of turbulent energy cascade in forced periodic turbulence

Contact : Martin Obligado (équipe EDT)

Résumé/Abstract : We investigate local-instantaneous scale-by-scale energy budgets in forced periodic turbulence, by exploiting the fully generalised form of the Karman-Howarth equation (Hill, J. Fluid Mech., vol.468, 2002, pp.317-326). In so doing, we elucidated that exchanges of turbulent energy across scales and space are characterised by very intense and intermittent spatio-temporal fluctuations of the time-derivative term, the spatial turbulent transport of fluctuating energy and the pressure-velocity term ; besides, these fluctuations are correlated with each other and with the intense intermittent fluctuations of the interscale energy transfer rate (Yasuda & Vassilicos, J. Fluid Mech., vol. 853, pp. 235-252). Such significant fluctuations and correlations are hidden in the classical Karman-Howarth equation (Karman & Howarth, Proc. R. Soc. Lond. A, vol.164, 1938, pp.192-215) as a consequence of relying on the statistical assumption of spatial homogeneity. Our new data analysis method based on local-instantaneous scale-by-scale energy budgets can be useful for discovering spatio-temporal intermittent features of turbulent energy cascade in other turbulent flows.