Numerical Prediction of the Vertical Responses of Planing Hulls in Regular Head Waves

Ferdi Çakıcı,Ali Doğrul,Emre Kahramanoğlu

doi:10.3390/jmse8060455

Ferdi Çakıcı, Ali Doğrul + Show 1 more

Open Access

https://doi.org/10.3390/jmse8060455

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Abstract

The evaluation of the hydrodynamic performance of planing vessels has always been one of the most attractive study fields in the maritime agenda. Resistance and self-propulsion studies have been performed using experimental and numerical methods by researchers for a long time. As opposed to this, the seakeeping performance of planing hulls is assessed with 2D approximation methods, but limitedly, while the experimental campaign is not cost-effective for several reasons. With this motivation, pitch and heave transfer functions and accelerations were obtained for a monohedral hull and a warped hull using a state of art commercial Reynolds-averaged Navier–Stokes (RANS) solver, in this study. Moreover, 2-DOF (degree of freedom) dynamic fluid–body interaction (DFBI) equations were solved in a coupled manner with an overset mesh algorithm, to find the instantaneous motion of the body. After verification, obtained numerical results at three different Froude numbers and a sufficiently large wave frequency range were compared with the experiments. The results showed that the employed RANS method offers a very accurate prediction of vertical motions and accelerations for planing hulls.

Highlights

Planing hulls have been widely used recently for commercial and military purposes in the naval architecture sector
The hydrodynamic investigation of planing hulls is relatively tougher compared to displacement type ships, due to several complex phenomena which are primarily caused by large motions of the body inside fluids
The most known experimental study was conducted by Fridsma [2], that covers the behaviors of the prismatic hull forms in both calm water and regular head waves

Summary

Introduction

Planing hulls have been widely used recently for commercial and military purposes in the naval architecture sector. The cornerstone research was conducted by Zarnick [8,9], where he proposed a mathematical model that predicts the vertical motions of planing hulls in regular and irregular head waves This method simplifies the 3D problem into a 2D water entry problem, and allows one to calculate the pitch and heave motions. Ghadimi et al [13] developed another mathematical model which is based on Algarin and Tacson’s studies [14,15] for the coupled heave and pitch motions of planing hulls at non-zero heel angle in regular head waves, and they validated the numerical results with the experimental data of several benchmark models.

Physics Modelling

Seakeeping Analyses

Motion RAOs