Free vibration of cantilevered composite plates in air and in water

Experimental study of the steady fluid–structure interaction of flexible hydrofoils

“…Recent studies of free vibrations of cantilever composite plates in air and water, with the same carbon fiber orientation as used in the present study, have shown that the frequency response is 50-70% lower in water than in air, due to large added mass effects (Kramer et al, 2013). This demonstrates that in some cases a simple added mass correction for bending only may not provide an acceptable estimate.…”

Parametric excitations and lock-in of flexible hydrofoils in two-phase flows

“…A major implication of the presence of modulated frequencies for cavitating systems is the added risk for primary parametric resonance: a case if the parametric excitations occur at twice of one of the system natural frequencies, for which vibrations may get much higher than for the case with classical resonance. It is important to note that the topic of parametric excitations due to density variations is also relevant for a wide range of multiphase flow problems; examples include boiling or cavitating flows inside or outside pipes (Klein, 1981), surface piercing foils/propellers (Motley et al, 2013;Kramer et al 2013;Young and Savander, 2011;Young and Kinnas, 2004;Young and Kinnas, 2002), and parametric roll excitations of marine vessels (Umeda et al, 2004;France et al, 2003). Parametric excitations may also be induced by gravity waves (Joubaud et al, 2012) and by periodic large-scale vortex shedding of lightweight natural and artificial swimmers (e.g.…”

“…flutter and divergence instability conditions (see Chae et al (2013) for more details), (single-phase) vortex-induced vibration and lock-in of flexible foils (see Chae et al (2015) for more details), and other resonant conditions (e.g. Young, 2008;Motley et al, 2013;Kramer et al, 2013).…”

Numerical and experimental study of a nearby solid boundary and partial submergence effects on hydrofoil added mass

“…Great theoretical, experimental and computational efforts have been devoted to this topic [13,2,7] and from the very beginning the authors realized about the significance of the problem's boundary conditions. Even when Blevins [1] published a collection of formulas referred to natural frequencies and mode shapes, several of them referenced to the effect of lateral walls.…”