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论文类型：期刊论文

发表时间：2016-01-01

发表刊物：NUCLEAR FUSION

收录刊物：SCIE、EI、Scopus

卷号：56

期号：1

ISSN号：0029-5515

关键字：macroinstabilities; plasma turbulence; gyrofluid and gyrokinetic simulations

摘要：Effect of shear flow on the multi-scale nonlinear interaction in plasmas is numerically investigated by using a self-consistent Landau-fluid model. Dual roles of shear flow in the process are discovered, significantly suppressing micro-scale fluctuations and dramatically promoting macro-scale fluctuations. Furthermore, its similar dual roles in turbulent transport are also demonstrated. The novel underlying mechanism for the nonlinear promotion is identified as the formation of a large vortex flow inside magnetic island, which as a common phenomenon have been often observed in space and magnetic fusion plasmas. The theoretical prediction on the threshold of shear flow based on an analytical modeling is verified via numerical simulations.