# Fluid Mechanics and Acoustics Laboratory - UMR 5509

LMFA - UMR 5509
Laboratoire de Mécanique des Fluides et d’Acoustique
Lyon
France

## Coverpage PRL 2019

Power fluctuations in turbulence [with Rémi Zamansky (IMFT)]

How universal are the power-fluctuations measured in the electricity output of a windmill? Indeed, the power fluctuation experienced by a windmill blade are determined by the power absorbed by the incoming, turbulent airflow. The universal character of turbulent power fluctuations is, in general, of major importance in the modeling and understanding of fluid flows in industry, geophysics and astrophysics. However, the manner in which the turbulence is generated can be radically different in different types of flows, so that it seems improbable that universality is observed among different types of flow. Nevertheless, we show that different turbulence generating mechanisms can lead to similar statistics of the energy input since the input is not only determined by the forcing mechanism, but also by the turbulent flow itself.