2004/05/01 by Nicolas Leprovost, Louis Marié, Bérengère Dubrulle +1
Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Angular velocity #Classical mechanics #Computer science #Constant (computer programming) #Flow (mathematics) #Forcing (mathematics) #Inertia #Langevin equation #Mechanics #Noise (video) #Physics #Power (physics) #Statistical Mechanics and Entropy #Thermodynamics #Torque #Turbulence #cond-mat.other #physics.flu-dyn #stochastic dynamics and bifurcation
paper · pdf · doi:10.1140/epjb/e2004-00177-x
published as European Physical Journal B 39 (2004) 121-129
openalex publication_date 2004/05/01 · arxiv created 2007/10/10 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
A stochastic model is derived to predict the turbulent torque produced by a swirling flow. It is a simple Langevin process, with a colored noise. Using the unified colored noise approximation, we derive analytically the PDF of the fluctuations of injected power in two forcing regimes: constant angular velocity or constant applied torque. In the limit of small velocity fluctuations and vanishing inertia, we predict that the injected power fluctuates twice less in the case of constant torque than in the case of constant angular velocity forcing. The model is further tested against experimental data in a von Karman device filled with water. It is shown to allow for a parameter-free prediction of the PDF of power fluctuations in the case where the forcing is made at constant torque. A physical interpretation of our model is finally given, using a quasi-linear model of turbulence.