Kinematic Alpha Tensors and dynamo mechanisms in a von Karman swirling flow
TypeArticles dans des revues avec comité de lecture
We provide experimental and numerical evidence of in-blades vortices in the von Karman swirling flow. We estimate the associated kinematic α-effect tensor and show that it is compatible with recent models of the von Karman Sodium (VKS) dynamo. We further show that depending on the relative frequency of the two impellers, the dominant dynamo mechanism may switch from α^2 to α − Ω dynamo. We discuss some implications of these results for VKS experiments.
Showing items related by title, author, creator and subject.
SAINT-MICHEL, Brice; DUBRULLE, Bérengère; MARIÉ, Louis; RAVELET, Florent; DAVIAUD, François (APS, 2013)We study the influence on steady turbulent states of the forcing in a von Karman flow, at constant impeller speed, or at constant torque. We find that the different forcing conditions change the nature of the stability of ...
SAINT-MICHEL, Brice; DUBRULLE, Bérengère; MARIÉ, Louis; RAVELET, Florent; DAVIAUD, François (2014)We present a detailed study of a global bifurcation occuring in a turbulent von Kármán swirling flow. In this system, the statistically steady states progressively display hysteretic behaviour when the Reynolds number is ...
ZAARAOUI, Abdelkader; RAVELET, Florent; MARGNAT, Florent; KHELLADI, Sofiane (Elsevier, 2013)A prototype device for measuring the volumetric flow-rate by counting vortices has been designed and realized. It consists of a square-section pipe in which are placed a two-dimensional bluff body and a strain gauge force ...
RAVELET, Florent; BAKIR, Farid; KHELLADI, Sofiane; REY, Robert (Elsevier, 2013)This article presents an experimental study of the hydraulic transport of very large solid particles (above 5 mm) in an horizontal pipe. Two specific masses are used for the solids. The solids are spheres that are large ...
DANLOS, Amélie; MÉHAL, Jean-Elie; RAVELET, Florent; COUTIER-DELGOSHA, Olivier; BAKIR, Farid (ASME, 2014)Instabilities of a partial cavity developed on a hydrofoil, a converging-diverging step, or in an interblade channel have already been investigated in many previous works. The aim of this study is to evaluate a passive ...