Hydroelastic response of floating elastic discs to regular waves. Part 1. Wave basin experiments

Abstract

A series of wave basin experiments is reported that investigates the flexural response of one or two floating thin elastic discs to monochromatic waves. The work is motivated by numerical model validation. Innovative techniques are used to ensure the experimental configuration is consistent with the model. This demands linear motions, time-harmonic conditions, homogeneity of the plate and the restriction of horizontal motions of the disc or discs. An optical remote sensing device is employed to record the deflection of the discs accurately. Tests involving a single disc and two discs are conducted for a range of disc thicknesses, incident wave steepnesses, frequencies and, in the case of two discs, geometrical arrangements. A data processing technique is used to decompose the raw data into its spectral harmonics and filter the higher-order components. Pointwise comparisons of the linear first-order component of the experimental deflection with numerical predictions are presented. Satisfying agreement is found, although the model consistently over predicts the deflection. Disc–disc interactions are observed in the two-disc tests. A brief discussion of the shortcomings of the pointwise analysis, with associated possible sources of discrepancy, provides a link to the study reported in Part 2 (Montiel et al. J. Fluid Mech., vol. 723, 2013, pp. 629–652).

Hydrodynamic responses of a thin floating disk to regular waves

“…Previously, Montiel et al (2013aMontiel et al ( , 2013b presented measurements of the flexural motions of a thin plastic disk in response to regular incident waves, as functions of the incident frequency. They used three thin disks, with H/D = 2.1 × 10 −3 to 6.9 × 10 −3 , and incident waves with lengths ranging from λ/D ≈ 0.63-3.14, and two small steepnesses ka ≈ 0.03 and 0.06.…”

Water wave transmission by an array of floating discs

“…Montiel et al [31,32] provided the only previous related validation. However, Montiel et al [31,32] applied artificial restraints to the disc to match the model assumptions as part of the experimental set-up. In particular, a rod was used to restrict surge motions, and a barrier was attached to the edge of the disc to prevent wave overwash.…”

Experimental and theoretical models of wave-induced flexure of a sea ice floe

“…Montiel et al 14,15 conducted a series of laboratory wave basin experiments to validate the linear theoretical model of wave interactions with an ice floe. In keeping with the theoretical models, they used a thin (plastic) plate to model the ice floe.…”

“…Tests were conducted for regular incident waves, using a range of wave periods and two mild steepnesses. Notably, Montiel et al 14,15 applied constraints to the model floe to match the assumptions of the theoretical models. They suspended a vertical rod through a small hole in the center of the floe to eliminate surge and drift, and used an edge barrier to prevent overwash.…”