Statistical Distributions of Sea Surface Elevations

AbstractThe problem is studied both theoretically and experimentally. Statistical distributions of the total curvature and the reciprocal to the total curvature at the specular points (SP) of a random Gaussian uniform sea surface are discussed. The theoretical distribution and its asymptotes are completely investigated. The validity of the theoretical distribution is verified by numerical simulations and natural experiments. In the experimental study of this distribution, Sun glint images taken with a high time and spatial resolution digital camera are used. Those images are developed by using a specially-designed Fortran program which calculates the statistical characteristics of the glints. The experimentally derived distribution of the glint areas is compared with the theoretical distribution. The main causes (origins) of small divergence between the theoretical and experimental results are discussed.

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Statistical Distributions Sea Surface Slope

Simulation of the Sea Surface for Remote Sensing - Springer Oceanography ◽

10.1007/978-3-030-58752-9_2 ◽

2020 ◽

pp. 21-52

Author(s):

Alexander Zapevalov ◽

Konstantin Pokazeev ◽

Tatiana Chaplina

Keyword(s):

Sea Surface ◽

Statistical Distributions ◽

Surface Slope

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Prediction of Slamming Occurrence on Catamaran Cross Structures

21st International Conference on Offshore Mechanics and Arctic Engineering, Volume 4 ◽

10.1115/omae2002-28344 ◽

2002 ◽

Cited By ~ 1

Author(s):

Kristoffer Grande ◽

Jinzhu Xia

Keyword(s):

Impact Velocity ◽

High Speed ◽

Sea Surface ◽

Statistical Distributions ◽

Velocity Impact ◽

Expected Frequency ◽

Strip Theory ◽

Wave Slamming ◽

Random Seaway ◽

Initial Results

In this paper, we study the problem of wave slamming on the cross structures of both fast ferry type catamarans and ocean going racing sailing catamarans. The emphasis is given to the prediction of the statistical distributions of slamming occurrence and slamming pressure magnitudes in a random seaway. A partly non-linear high-speed strip theory sea-keeping program is used to calculate the vessel motions and the relative motions between any part of the hull and the sea surface, including slamming impact velocity. Impact velocities are classified in 5 groups, and slamming pressures calculated for each group. To calculate vessel motions of heeled sailing catamarans a strip method for an asymmetric multi-hull is developed; the theory and initial results are presented. An investigation into the effect of sail forces on motions and slamming occurrence is also performed. The sail forces are found to be an important factor in predicting motions of sailing catamarans. The procedure proposed in this paper gives the necessary information to estimate the maximum slamming pressures the vessel is likely to encounter and equally importantly the expected frequency of lighter slams, which is useful for fatigue calculations.

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