The diffraction coefficient on a submerged horizontal cylinder for fixed values of the radius ( and ) and of the submergence of the cylinder center ( and ). The mean JONSWAP spectrum has been assumed.
The dimensionless coefficient [Eq. (21)] as a function of for fixed values of the submergence of cylinder center . The mean JONSWAP spectrum has been assumed.
What happens when a positive peak of the horizontal force on the cylinder occurs (the peak occurs at time instant ): the time histories of the force components and for and . The mean JONSWAP spectrum has been assumed for the surface displacement.
Experiment gauges: the 16 pressure transducers assembled on the median vertical section of the solid cylinder (transducers 1–8) and on the radiant crown (transducers ).
The diffraction coefficient of the wave pressure, on the cylinder surface. The continuous lines represent the theoretical distribution from Eq. (12) with experimental values of and (frequency spectrum is the mean JONSWAP).
The experimental values of vs . Left panel: cylinder. Right panel: cylinder.
The experimental values of vs , for cylinder radius . Dashed line gives the linear regression.
The cylinder. The values of the quotient between standard deviation of experimental horizontal force and standard deviation of theoretical force, as a function of the Keulegan-Carpenter number .
Comparison between experimental values of for the cylinder, and analytical predictions (continuous line) obtained from Eq. (21) for a mean JONSWAP spectrum.
Record No. 516 ( and ). What happens when a very large height of the pressure fluctuation occurs at transducer 1 (see Fig. 5). Dotted lines are obtained from experimental data. Continuous lines show analytical predictions obtained from Eqs. (26)–(28), using experimental values of and ; theoretical spectrum is the mean JONSWAP (all the time histories are normalized).
The theoretical phase lags , , and on the solid cylinder, when a large pressure wave occurs at point . Predictions are obtained from Eq. (26), for , and ; the mean JONSWAP spectrum has been assumed. Let us note that gives the time that the wave pressure takes to pass from point to point (points and have equal submergence and are on the solid cylinder).
The phase lags , and on the equivalent water cylinder, when a large pressure wave occurs at point in an undisturbed wave field. Predictions are obtained for , and ; the mean JONSWAP spectrum has been assumed. Let us note that gives the time that the wave pressure takes to pass from point to point (points and have equal submergence and are on the equivalent water cylinder).
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