Structured input–output analysis of stably stratified plane Couette flow
نویسندگان
چکیده
We employ a recently introduced structured input-output analysis (SIOA) approach to analyze streamwise and spanwise wavelengths of flow structures in stably stratified plane Couette flow. In the low-Reynolds number ($Re$) low-bulk Richardson ($Ri_b$) spatially intermittent regime, we demonstrate that SIOA predicts high amplification associated with corresponding characteristic oblique turbulent bands this regime. also identifies quasi-horizontal resembling turbulent-laminar layers commonly observed high-$Re$ high-$Ri_b$ An across range $Ri_b$ $Re$ values suggests classical Miles-Howard stability criterion ($Ri_b\leq 1/4$) is change most amplified when Prandtl close one ($Pr\approx 1$). However, for $Pr\ll 1$, are determined by product $PrRi_b$. For $Pr\gg another structure show principally density perturbations. further dominance density-associated $Pr$ limit constructing analytical scaling arguments terms under assumptions unstratified (with $Ri_b=0$) invariance.
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ژورنال
عنوان ژورنال: Journal of Fluid Mechanics
سال: 2022
ISSN: ['0022-1120', '1469-7645']
DOI: https://doi.org/10.1017/jfm.2022.648