準最適制御による乱流摩擦抵抗低減のレゾルベント解析

抄録

The objective of the present study is to elucidate the drag reduction mechanism by the suboptimal control for turbulent friction drag reduction by conducting the resolvent analysis. In the analysis, the turbulent velocity field is expressed as a linear superposition of propagating modes, identified via a gain-based decomposition of the Navier-Stokes equations. This decomposition enables targeted analyses of the effects of control on coherent turbulent structures such as the near-wall cycle (NW-modes) and very-large-scale motions (VLSMs). In the present study, we investigate the effect of suboptimal control on these turbulent structures.