Read Books Online and Download eBooks, EPub, PDF, Mobi, Kindle, Text Full Free.
Simmolo A Nonlinear Time Domain Program For The Simulation Of Wave Induced Motions And Loads Of A Ship
Download Simmolo A Nonlinear Time Domain Program For The Simulation Of Wave Induced Motions And Loads Of A Ship full books in PDF, epub, and Kindle. Read online Simmolo A Nonlinear Time Domain Program For The Simulation Of Wave Induced Motions And Loads Of A Ship ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Book Synopsis SIMMOLO, a Nonlinear Time-domain Program for the Simulation of Wave-induced Motions and Loads of a Ship by : L. J. M. Adegeest
Download or read book SIMMOLO, a Nonlinear Time-domain Program for the Simulation of Wave-induced Motions and Loads of a Ship written by L. J. M. Adegeest and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Time-domain Simulation of Nonlinear Ship Motions and Wave Loads by :
Download or read book Time-domain Simulation of Nonlinear Ship Motions and Wave Loads written by and published by . This book was released on 1999 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the assessment of the ability of a ship structure to withstand specified sea environments with an acceptable risk of failure, accurately predicted loads are vital. Of paramount importance are extreme loads on the hull structure, which usually occur when a ship undergoes large heaving & pitching motions in rough seas, sometimes accompanied by impacts between the bow & waves. This paper describes the application of strip theory to time domain calculations of non-linear ship motions and hull-girder loads in head seas. In this approach, the differential equations of ship motion are solved numerically by calculating hydrodynamic forces & coefficients at each time step by strip theory, taking into account nonlinearities relating to large relative motion between waves & the ship hull. The results indicate the usefulness of this approach compared to the conventional linear frequency-domain approach.
Book Synopsis Three Dimensional Time Domain Simulation of Ship Motions and Loads in Large Amplitude Head Waves by : Olgun Guven Hizir
Download or read book Three Dimensional Time Domain Simulation of Ship Motions and Loads in Large Amplitude Head Waves written by Olgun Guven Hizir and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This PhD thesis presents the development of a practical computational tool named Large Amplitude RESponse (LARes), based on 3D quasi-non-linear time-domain technique, to predict ship motions and loads in large amplitude waves which can be accessible to ship designers. Firstly, a linear 3-D Green source panel code (LARes L1) was developed to perform linear time-domain analysis ship motion and internal load simulations based on the frequency-domain hydrodynamic coefficients which were calculated in the linear PRECAL software. Linear simulations are validated with the linear time-domain PRETTI software results using rectangular barge geometry. The motions, internal loads, global and sectional hydrodynamic forces were agreed well with the linear PRETTI model results in zero and forward speed simulations. Then, non-linear time-domain panel code (LARes L2) was developed in order to predict ship motions and loads in large amplitude waves using the Froude-Krylov nonlinearity level. At each time step, the exact wetted area of the ship surface under the wave profile was calculated and fed in the time-domain motion and load equations while the diffraction and radiation forces were kept as linear. The present program achieved good agreement with the non-linear PRETTI model results both for the barge and S175 container geometries at zero and forward speed conditions in small amplitude waves. Moreover, the S175 container ship results are compared with the available experimental data and agreed well with the experimental results in forward speed case. It has been observed that PRETTI code is over-estimating motion and load responses especially around the resonant frequency due to the surge motion influence in the memory forces evaluations. In the Froude-Krylov nonlinear level predictions, it has been observed that PRETTI diverges from the experimental results when the wave steepness is higher than 0.08 due to the linear radiation and diffraction forces. Based on the same framework, a more advanced nonlinear time-domain panel code (LARes L3) was developed in order to investigate the effects of quasi-non-linear diffraction and radiation forces in large amplitude ship simulations. A new mesh generator was introduced in order to cut and correct the original panels under the still water level in the updated position of the ship after displacements and rotations. The quasi-non-linear diffraction and radiation forces were calculated at the pre-defined position cases and stored in a database. In order to lower the computational cost multi-dimensional integration and interpolation codes were generated. The S-175 containership was tested in 120 different position cases and resulting hydrodynamic coefficients and forces were stored in the database. The results of the LARes L3 model were compared with the available experimental data using the S-175 containership in forward speed. The computed motion responses showed a good agreement with the experimental data. Moreover, three of the developed models are compared with the experiments and their performances were investigated with respect to the increasing wave slope. In addition to that, the effect of the wave length and ship speed in large amplitude waves are investigated in detail. Non-linear behaviors of the codes were compared with the experimental results which showed a good agreement. Finally, the Vertical Shear Force (VSF) and Vertical Bending Moment (VBM) responses were investigated in large amplitude motions. It was observed that, in the validation section, numerical model peak amplitudes showed well agreement with the experimental results, but they were observed to be shifted to the higher frequencies compared to the experimental results. The reason for that was attributed to the longitudinal mass distribution on the ship in the experimental setup which had not been provided in detail in the published experimental results.
Book Synopsis Time-domain Simulation of Wave-induced Ship Motions by a Rankine Panel Method by : Junshi Wang
Download or read book Time-domain Simulation of Wave-induced Ship Motions by a Rankine Panel Method written by Junshi Wang and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, a numerical program has been developed to simulate the wave-induced ship motions in the time domain. Wave-body interactions have been studied for various ships and floating bodies through forced motion and free motion simulations in a wide range of wave frequencies. A three-dimensional Rankine panel method is applied to solve the boundary value problem for the wave-body interactions. The velocity potentials and normal velocities on the boundaries are obtained in the time domain by solving the mixed boundary integral equations in relation to the source and dipole distributions. The hydrodynamic forces are calculated by the integration of the instantaneous hydrodynamic pressures over the body surface. The equations of ship motion are solved simultaneously with the boundary value problem for each time step. The wave elevation is computed by applying the linear free surface conditions. A numerical damping zone is adopted to absorb the outgoing waves in order to satisfy the radiation condition for the truncated free surface. A numerical filter is applied on the free surface for the smoothing of the wave elevation. Good convergence has been reached for both forced motion simulations and free motion simulations. The computed added-mass and damping coefficients, wave exciting forces, and motion responses for ships and floating bodies are in good agreement with the numerical results from other programs and experimental data.
Book Synopsis Nonlinear Analysis of Waves Induces Motions and Loads in Large Amplitude Waves by : Giuseppe Mortola
Download or read book Nonlinear Analysis of Waves Induces Motions and Loads in Large Amplitude Waves written by Giuseppe Mortola and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: An ocean going vessel, sailing in severe seas, experiences motions and loads that are largely a ected by nonlinear phenomena. These effects deviate the responses from the linear prediction, modifying their magnitudes, symmetry and frequency characteristics. The change of the actual wetted geometry due to motions and large ambient waves elevation and the occurrence of impulsive phenomena, such as bottom impact, are some of the main sources of nonlinearities. Current state-of-art in seakeeping, applied to ship design, is based on the assumption of small amplitude motions and linearity between the excitation and the response. These techniques have been proved, during the years, to be reliable for small and moderate sea states, but they are not effective in large amplitude waves. The understanding and prediction of the behaviour of the vessel in rough seas is of crucial importance for its design, and therefore there is a need for better methods and practices. Application of nonlinear seakeeping methods in a every-day design situatons is limited. The complexity and the computational cost of some methodologies, together with the absence of standardised procedures, are the main causes for the reduced use of such a methodologies. The work presented in this thesis aims to develop a practical nonlinear seakeeping approach that can be used in a design content to model wave induced motions and loads in large amplitude waves. The wave-body interaction problem is solved using a time domain nonlinear two dimensional approach, that considers the actual wetted hull portion and the relative velocity between the structure and the waves. The vessel is modelled as a flexible body to allow structural dynamics. The proposed formulation takes into account impulsive phenomena due to water impact, on both the bottom and the flare of the hull, using a combination of analytical and empirical techniques. The proposed methodology is applied to the S-175 and the Wils II 13,000 TEU container ships. The validation of the proposed method, conducted in both small and large amplitude regular waves, shows the capability of the technique to correctly predict the behaviour of the vessel also when linear methodologies fail. The analysis demonstrates the importance and the reliability of hydroelastic methods for the prediction of wave induced loads, especially when whipping is relevant. A procedure, which applies the proposed methodology for the evaluation of maximum expected values of wave induced motions and loads is presented. Long term analyses are conducted, using both linear and nonlinear method, to study the effect of nonlinearities. The comparison between linear and nonlinear approaches shows an increase of maximum load responses when nonlinear hydroelasticity is applied. This study highlights also the dependency of the results on the selection of the return period and operational velocity profile of the vessel.
Book Synopsis The Effects of Wave Groups on the Nonlinear Simulation of Ship Motion in Random Seas by : Jeffrey A. Richer
Download or read book The Effects of Wave Groups on the Nonlinear Simulation of Ship Motion in Random Seas written by Jeffrey A. Richer and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Historically, the analysis of ship motion and loading responses has been performed in the frequency domain with both linear response amplitude operators and wave energy density spectra. This method, therefore, did not account for the nonlinear nature of waves. A more precise method is to obtain the response in the time domain, processing non-linear wave data with a linear response amplitude operator. Since the input is non-linear, even though the system is linear, the output will also be non-linear. This resultant data can then be used to generate a more accurate design of seaworthy vessels. Furthermore the linear frequency domain method does not account for the presence or effects of wave groups. This study shows the improved accuracy in the response obtained by accounting for non-linearities and furthermore indicates that wave groups affect the vertical relative motion of a moored ship (zero-speed).
Book Synopsis Extreme Response of Nonlinear Ocean Structures by : Rune Torhaug
Download or read book Extreme Response of Nonlinear Ocean Structures written by Rune Torhaug and published by . This book was released on 1996 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Advances in Numerical Simulation of Nonlinear Water Waves by : Qingwei Ma
Download or read book Advances in Numerical Simulation of Nonlinear Water Waves written by Qingwei Ma and published by World Scientific. This book was released on 2010 with total page 700 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ch. 1. Model for fully nonlinear ocean wave simulations derived using Fourier inversion of integral equations in 3D / J. Grue and D. Fructus -- ch. 2. Two-dimensional direct numerical simulations of the dynamics of rogue waves under wind action / J. Touboul and C. Kharif -- ch. 3. Progress in fully nonlinear potential flow modeling of 3D extreme ocean waves / S.T. Grilli [und weitere] -- ch. 4. Time domain simulation of nonlinear water waves using spectral methods / F. Bonnefoy [und weitere] -- ch. 5. QALE-FEM method and its application to the simulation of free-responses of floating bodies and overturning waves / Q.W. Ma and S. Yan -- ch. 6. Velocity calculation methods in finite element based MEL formulation / V. Sriram, S.A. Sannasiraj and V. Sundar -- ch. 7. High-order Boussinesq-type modelling of nonlinear wave phenomena in deep and shallow water / P.A. Madsen and D.R. Fuhrman -- ch. 8. Inter-comparisons of different forms of higher-order Boussinesq equations / Z.L. Zou, K.Z. Fang and Z.B. Liu -- ch. 9. Method of fundamental solutions for fully nonlinear water waves / D.-L. Young, N.-J. Wu and T.-K. Tsay -- ch. 10. Application of the finite volume method to the simulation of nonlinear water waves / D. Greaves -- ch. 11. Developments in multi-fluid finite volume free surface capturing method / D.M. Causon, C.G. Mingham and L. Qian -- ch. 12. Numerical computation methods for strongly nonlinear wave-body interactions / M. Kashiwagi, C. Hu and M. Sueyoshi -- ch. 13. Smoothed particle hydrodynamics for water waves / R.A. Dalrymple [und weitere] -- ch. 14. Modelling nonlinear water waves with RANS and LES SPH models / R. Issa [und weitere] -- ch. 15. MLPG_R method and Its application to various nonlinear water waves / Q.W. Ma -- ch. 16. Large Eddy simulation of the hydrodynamics generated by breaking waves / P. Lubin and J.-P. Caltagirone -- ch. 17. Recent advances in turbulence modeling for unsteady breaking waves / Q. Zhao and S.W. Armfield -- ch. 18. Freak waves and their interaction with ships and offshore structures / G.F. Clauss
Book Synopsis Theoretical Manual for SEALOADS, Version 1.1: by :
Download or read book Theoretical Manual for SEALOADS, Version 1.1: written by and published by . This book was released on 2001 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report outlines the theoretical background in the FORTRAN program SEALOADS version 1.1 for computing non-linear ship motions, bending moments & shear forces on the hull, and hydrodynamic pressure distributions over the wetted hull surface. After an introduction to the program, chapter 2 describes the non-linear equations of ship motion, the initial boundary-value problem, and the linearized radiation & diffraction problems. Pressure distributions over the wetted surface are discussed in chapter 3. The computation of Froude-Krylov forces, bow-flare impact forces, viscous & other non-linear forces, and hydrodynamic sea loads are the focus of chapter 4. Chapter 5 presents variable hydrodynamic coefficients and an automatic panel generator. The final chapter suggests further work to obtain a more powerful & reliable tool for predicting ship motions & loads in extreme seas.
Book Synopsis Numerical Methods for Seakeeping Problems by : Bettar O. el Moctar
Download or read book Numerical Methods for Seakeeping Problems written by Bettar O. el Moctar and published by Springer. This book was released on 2021-02-18 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book describes currently applied and newly developed advanced numerical methods for wave-induced ship motions and loads. Besides well-established computational methods based on strip theory, panel methods and finite volume methods for unsteady Reynolds-averaged Navier-Stokes equations (URANS), recent advances like a fully nonlinear Rankine panel method, URANS calculations including elastic hull deformations, and an improved method to predict added resistance in waves are explained in detail. Furthermore, statistical methods to assess extreme motions and loads are described both for linear and nonlinear responses in a stationary seaway as well as during long-term ship operations. Results of motions and loads, computed using the various methods, are compared with each other and with results of model experiments. Introductory chapters on fluid dynamics, motions of rigid and elastic ship hulls, numerical methods to compute fluid flows associated with wind waves, and the development and simulation of seaways complement the volume. The book will be of interest to post-graduate students, PhD candidates, as well as engineers in the field of naval architecture, ocean, and marine engineering.
Book Synopsis Time domain simulation of ship motions in waves by : Edward John Ballard
Download or read book Time domain simulation of ship motions in waves written by Edward John Ballard and published by . This book was released on 2002 with total page 295 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis A Time Domain Simulation of Ship Motions in Waves by :
Download or read book A Time Domain Simulation of Ship Motions in Waves written by and published by . This book was released on 1988 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Wave-induced Loads and Ship Motions by : Lars Bergdahl
Download or read book Wave-induced Loads and Ship Motions written by Lars Bergdahl and published by . This book was released on 2008 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Model Testing and Numerical Simulations of Seakeeping Performance for High-Speed Vessels by :
Download or read book Model Testing and Numerical Simulations of Seakeeping Performance for High-Speed Vessels written by and published by . This book was released on 2004 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book SHIPMO7 written by Kevin A. McTaggart and published by . This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This manual describes a new version of the ship motion program SHIPMO, called SHIPMO7. The new version introduces several improvements over previous versions. A new boundary element method for computing sectional hydrodynamic coefficients eliminates problems with irregular frequencies. The revised program computes sea loads, including appendage forces and viscous forces, with special attention to the consistent treatment of forces acting on the ship during both motion and load predictions. The program also has revised input and output format to improve consistency and clarity. SHIPMO7 also gives derived responses, including local accelerations, slamming, deck wetness, motion-induced interruptions, and added resistance in waves. Information is included on running the program, and sample inputs and outputs are appended.
Book Synopsis On the Calculation of Maxima of Non-linear Wave Forces and Wave Induced Motions by : Tor Vinje
Download or read book On the Calculation of Maxima of Non-linear Wave Forces and Wave Induced Motions written by Tor Vinje and published by . This book was released on 1976 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Wave Induced Motions and Loads on Ships in Oblique Waves by : R. Wahab
Download or read book Wave Induced Motions and Loads on Ships in Oblique Waves written by R. Wahab and published by . This book was released on 1974 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:
