INTRODUCTION This paper focuses on the development of optimal deterministic, nonlinearly coupled barge motion models, identification of their system parameters and calibration of their prediction capability using experimental results. The ultimate objective is to develop accurate yet sufficiently low degree-offreedom stochastic models suitable for efficient probabilistic stability and reliabili...

0045-7930/$ see front matter 2010 Elsevier Ltd. A doi:10.1016/j.compfluid.2010.02.002 * Corresponding author. Tel.: +1 319 335 6381; fax E-mail address: [email protected] (P.M. Ca This paper aims at presenting the most resolved solutions to date for the ship forward speed diffraction and pitch and heave problems, and discuss the method that enables these computations. Large-scale DES comp...

Severe environment in deep ocean affects operating reliability and security of coring drill. Adopting heave motion signal measured by accelerometer to confirm heave compensation of coring drill, the compensation control method is proposed using disturbance observer to restrain the disturbance. Then, the disturbance observer is designed. The heave motion simulation for coring drill is done with ...

We show experimentally that properly selected chord-wise flexibility can have a significant effect on the propulsive efficiency of two-dimensional flapping (heaving and pithing) foils, up to a 36% increase, compared to the efficiency of a rigid foil, with small loss in thrust. Two different foil kinematics are employed in the experiments: the first using simple harmonic heave and pitch motions;...

Due to the fact that there is no static reference point in ocean space, relative measurement sensors such as laser cannot be applied of ship motion. In order collect motion signal a more accurately, an absolute method for proposed. Firstly, acceleration heave direction obtained by using sensor; secondly, time–frequency domain integration algorithm used avoid problem quadratic trend item and inf...

Wave energy converters (WECs) often include a submerged heave reaction plate located at a depth where the surrounding water is minimally disturbed by the passing surface waves. Heave plates provide a relatively stationary and artificially massive body to which WECs transfer the reactionary forces generated as their power-takeoffs (PTOs) resist the motion induced by the incoming waves. To date l...

Characteristics of heave compensation systems used on a marine drilling platform or drill-ship are analyzed. An active heave compensation system with two lift cylinders is proposed by COMRA (China Ocean Mineral Resources & Association), which will be used in 1000-m depth ocean poly-metallic nodule pilot mining system. A corresponding virtual prototype of this system is developed. The parametric...

A deepwater lifting operation using crane vessel is investigated by a time-domain analysis program for floating crane vessel systems. In the analysis, a coupled analysis of floating vessel and lifted object dynamics connected via crane wire are simulated with and without heave compensator. For deepwater installation cases, amplified vertical motion of lifted object is anticipated even under mil...

A parametric wave spectrum resembling procedure is applied to detect the sea state parameters, namely peak period and significant height, based on measurement analysis of heave pitch motions a vessel in seaway, recorded by smartphone located onboard ship. The system makes it possible determine acceleration spectra reference ship encounter frequency domain and, subsequently, absolute once motion...