Study On the Simulation Performance of Two-sided Segmented Wavemakers

Li, Jun (School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University) | Li, Xin (School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University) | Chen, Gang (School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University) | Lu, Haining (School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University)

OnePetro 

ABSTRACT:

Segmented wavemakers which consist of numerous individually programmed paddles have become important in the study of wave and its interaction with ocean engineering structures in ocean basin. There are some key problems greatly affecting the simulation quality of segmented wavemakers, including the limitation of direction angle of oblique wave simulation induced by paddle width and wave period, the generation of spurious waves and the effective test area of 3D shortcrested wave. The following results are obtained through the analysis of the performance of two-sided segmented wavemakers:(1)The relationship between oblique wave angle and wave period; (2)Wave direction limitation to prevent spurious waves; (3)Effective test area of simulated 3D short-crested wave. The results are significant to high quality wave simulation and providing better wave environment conditions for model tests of various ocean engineering structures in deep ocean basin.



INTRODUCTION


High quality simulation of winds, waves and currents in ocean engineering basin is a basic requirement for model tests of various ocean engineering structures under ocean environment conditions. Whether wave simulation is correct or not is crucial to the accuracy and reliability of model test results. Theoretically, the two-sided segmented wavemakers is capable of generating oblique long-crested wave in the directions between 0 and 270 degrees in the coordinates showed in Fig.1 (the angle is between wave propagation and –y axis), but in fact, we cannot obtain the ideal simulating results of oblique waves at arbitrary angles and arbitrary periods due to the influences of simulation method for oblique wave generated by segmented wavemakers and width of each paddle, etc. Meanwhile, Sand(1987)pointed out that one or more spurious waves different from target angle may be generated in wave basin when simulating an oblique wave if the ratio of width of each paddle to wavelength is greater than 1/2.