The response of an elastic splitter plate attached to a cylinder to laminar pulsatile flow

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• 作者：Anup Kundu^a ; Atul K. Soti^a ; Rajneesh Bhardwaj^b ; ^{rajneesh.bhardwaj@iitb.ac.in} ; Mark C. Thompson^c
• 关键词：Computational fluid dynamics (CFD) ; Fluid-Structure Interaction (FSI) ; Immersed boundary method (IBM) ; Pulsatile flow ; Flow-induced deformation ; Lock-in condition
• 刊名：Journal of Fluids and Structures
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：68
• 期：Complete
• 页码：423-443
• 全文大小：4980 K
• 卷排序：68

文摘

The flow-induced deformation of a thin, elastic splitter plate attached to the rear of a circular cylinder and subjected to laminar pulsatile inflow is investigated. The cylinder and elastic splitter plate are contained within a narrow channel and the Reynolds number is mostly restricted to Re=100, primarily covering the two-dimensional flow regime. An in-house Fluid-Structure Interaction code is employed for simulations, which couples a sharp-interface immersed boundary method for the fluid dynamics with a finite-element method to treat the structural dynamics. The structural solver is implicitly (two-way) coupled with the flow solver using a partitioned approach. This implicit coupling ensures numerical stability at low structure-fluid density ratios. A power spectrum analysis of the time-varying plate displacement shows that the plate oscillates at more than a single frequency for pulsatile inflow, compared to a single frequency observed for steady inflow. The multiple frequencies obtained for the former case can be explained by beating between the applied and plate oscillatory signals. The plate attains a self-sustained time-periodic oscillation with a plateau amplitude in the case of steady flow, while the superimposition of pulsatile inflow with induced plate oscillation affects the plateau amplitude. Lock-in of the plate oscillation with the pulsatile inflow occurs at a forcing frequency that is twice of the plate natural frequency in a particular mode and this mode depends on the plate length. The plate displacement as well as pressure drag increases at the lock-in condition. The percentage change in the maximum plate displacement, and skin-friction and pressure drag coefficients on the plate, due to pulsatile inflow is quantified. The non-linear dynamics of the plate and its coupling with the pulsatile flow are briefly discussed.