Ullmann, T.T.UllmannSchmid, B.B.SchmidManz, P.P.ManzMilligen, B. VanB. VanMilligenTovar, G.E.M.G.E.M.TovarRamisch, M.M.Ramisch2022-03-062022-03-062020https://publica.fraunhofer.de/handle/publica/26566010.1103/PhysRevE.102.063201In two-dimensional turbulent systems the redistribution of energy can be described by quadratic nonlinear three-wave interactions, which are limited by resonance conditions. The set of coupling modes can be understood as resonant manifold. It has been predicted by theory that, in the presence of a shear flow, the resonant manifold in wave-number space shrinks in time favoring large-scale structures. The phenomenon of manifold shrinking in the presence of shear flows is studied the first time experimentally in drift wave turbulence at the stellarator TJ-K by bicoherence analysis. By estimating effective mode numbers characterizing the width of the manifold, it is demonstrated that increasing shear leads to a shrinking of the resonance manifold.en660610620journal article