Flow-Induced Reconfiguration of and Force on Elastic Cantilevers

The reconfiguration of elastic beam-like structures (e.g. the foliage) that subjected to cross-flow is widely encountered in nature and engineering applications. Based on a fully coupled numerical algorithm, the fluid–structure interaction between elastic cantilever and cross-flow is investigated in this paper. The immersed boundary-lattice Boltzmann method (IB-LBM) is used to solve the flow involving moving boundaries. The elastic cantilevers are modeled as inextensible Euler-Bernoulli beams and their dynamics are governed by geometrically nonlinear equations. The results suggest that the flow-induced dynamics and fluid forces are sensitive to Cauchy number (Cy). In essence, the flow-induced reconfiguration of elastic cantilevers discussed in this paper is the superposition of large deformation and sustained oscillation. The amplitude as well as the periodicity of drag and lift force are significantly modulated by structure motion. A greater Cy is found to yield a lift force which is comparable with the drag force. The Cauchy-Reconfiguration number curve overall fits the empirical values, in addition to the underestimated values obtained by the present simulations, we attribute it to the streamlined morphology and fluid force in transverse.