二次元Momentumless Wakeの乱流間欠構造に関する研究〔流体工学, 流体機械〕

概要

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The u and v velocity components of a plane turbulent Momentumless Wake (injection adjust to provide a thrust exactly cancels the model's drag) were measured by the rake of X-wires. The autocorrelations show that large-scale eddies such as karman vortices in a wake are not generated downstream in the Momentumless Wake. The two point double correlations suggest that the momentumless wake is analogous to isotropic turbulence. The fluctuating velocity vectors indicate that the outward extent of the turbulent flows in the momentumless wake is associated with the intermittent blow up and mixing process. Dynamic structures in the Momentumless Wake are investigated by means of the POD. The consideration of the first three modes of the POD allows to precis the instantaneous characteristic structure which plays a dominant role in the dynamical properties of the momentumless wake. The results show that a few dominant wave numbers found in the first eigenvalue of the POD correspond to those of the unstable modes obtained from the linear stability theory.
社団法人日本機械学会の論文
1997-12-25