On the forced vibration of the fiber partially immersed in fluid

Energy harvesting from underwater base excitation of a piezoelectric composite beam

“…For completeness, the resonance frequencies (defined as the frequencies at which the magnitude of the transfer function is maximized) are reported in table 1 for the four selected submersion lengths L 2 = L/8, L/4, L/2, and L. Notably, the presence of the encompassing fluid produces a remarkable reduction of both the quality factor and the resonance frequency. Figure 6 suggests that the resonance frequency decreases as the submersion length increases, in agreement with the findings in [47][48][49][50]. This phenomenon should be ascribed to the increase in the overall added mass from the fluid as the immersion length increases.…”

“…In agreement with table 1, we find that also for open-circuited electrodes the resonance frequency decreases as the submersion length increases and that nonlinear added mass effects play a secondary role. We comment that the voltage output of the piezoelectric structure can be potentially utilized for inferring fluid properties along the lines of the sensor concept in [48,49]. When comparing table 2 with table 1 and figures 5 and 7, we observe modest variations of the resonance frequencies, which may be attributed to experimental uncertainty and possible increases of the mass of the structure due to water absorption.…”

“…Mechanical vibrations of cylinders and plates entirely submerged in quiescent viscous fluids have been widely studied in the literature across a broad range of physical and temporal scales [39][40][41][42][43][44][45][46]. However, vibration of partially submerged structures has been considered only in a few studies [47][48][49][50]. Specifically, the role of the free water surface on the hydrodynamic coefficients of a cantilever plate is investigated in [47].…”

“…Similar evidence is garnered in [50], with a focus on added mass effects. Partially submerged vibrating fibers are considered in [48,49], where theoretical and experimental analyses of optical viscometer based on partially submerged vibrating fibers are developed to elucidate the effect of density, viscosity, and liquid depth on the mechanical vibration. These efforts have demonstrated that the submersion length has a fundamental influence on the response of the immersed structure.…”