Pennino, Silvia (2014) Vertical Motion Assessment for Planing Hulls. [Tesi di dottorato]

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Item Type: Tesi di dottorato
Lingua: English
Title: Vertical Motion Assessment for Planing Hulls
Creators:
CreatorsEmail
Pennino, SilviaUNSPECIFIED
Date: 2014
Number of Pages: 150
Institution: Università degli Studi di Napoli Federico II
Department: Ingegneria Industriale
Scuola di dottorato: Ingegneria industriale
Dottorato: Ingegneria aerospaziale, navale e della qualità
Ciclo di dottorato: 26
Coordinatore del Corso di dottorato:
nomeemail
De Luca, Luigiluigi.deluca@unina.it
Tutor:
nomeemail
Begovic, ErminaUNSPECIFIED
Date: 2014
Number of Pages: 150
Uncontrolled Keywords: planing hulls seakeeping, 2D nonlinear time domain code, regular wave tests, vertical motions, bow accelerations, water impact wedge, warped hullforms
Settori scientifico-disciplinari del MIUR: Area 09 - Ingegneria industriale e dell'informazione > ING-IND/01 - Architettura navale
Date Deposited: 07 Apr 2014 12:50
Last Modified: 27 Jan 2015 11:06
URI: http://www.fedoa.unina.it/id/eprint/9848

Abstract

Planing hull forms are commonly used for fast patrol boats, pleasure craft, SAR vessels. Beside powering prediction, the seakeeping assessment and optimization are considered mostly important for their design. The aim of this Thesis was to develop a numerical method, accurate, robust and fast, to be used in design of fast small craft without excessive computational time necessity, for the calculation in time domain of planing boats vertical motions. The difficulties related to the description of planing hulls seakeeping physics through a set of mathematical equations led to the development of the two mathematical models. The complete theoretical models "non- linear time domain simulation" and "fully non- linear time domain simulation" were subsequently implemented in a numerical codes in Matlab-Simulink environment. Experimental program on warped planing hulls seakeeping, has been performed in Towing tank of Department of Industrial Engineering of University of Naples Federico II with aim to validate developed methodology. The availability of specific and dedicated experimental tests allowed to compare time series of experimental and numerical data results, not only typical values reported in literature, and furthermore to analyze them in the same manner. This synergy of numerical and experimental approaches resulted in accurate validation of developed methodology. Numerical and experimental heave, pitch and accelerations at CG and at bow for three model speeds for monohedral and for the most innovative warped hull form with variable angle of the bottom, representative of current trends, are analyzed in time domain and in frequency domain. From the spectral analysis was possible to determine the magnitude of the higher order harmonics, which are negligible for motions and significant for accelerations. Small non-linearity in the motions, results in a significant contribution of the higher order harmonics in accelerations. Nonlinearities in accelerations responses have been obtained by developed codes with high accuracy in whole speed and wave frequencies range. The developed fully non-linear mathematical model is accurate and reliable to be used in design of fast small craft seakeeping assessment. Future developments are concerning pressure distribution along the hull and responses calculations in irregular sea.

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