Mathematical Modeling Of Inland Vessel Maneuverability Considering Rudder Hydrodynamics

This book demonstrates that different rudder configurations have different hydrodynamic characteristics, which are influenced by the profile, the parameters, and the specific configuration. The author proposes new regression formulas to help naval architects quickly estimate the rudder-induced forces and moments in maneuvering. Furthermore, the author proposes and validates an integrated maneuvering model for both seagoing ships and inland vessels. Using the proposed regression formulas and maneuvering model, the specific impacts of rudder configurations on inland vessel maneuverability are studied. In turn, the book demonstrates the application of Reynolds-Averaged Navier–Stokes (RANS) simulations to obtain rudder hydrodynamic characteristics, and the integration of the RANS results into maneuvering models as an accurate estimation of rudder forces and moments needed to quantify the impacts of rudder configurations on ships’ maneuvering performance. In addition, the author proposes new criteria for the prediction and evaluation of inland vessel maneuverability. Simulations of ships with various rudder configurations are presented, in order to analyze the impacts of rudder configurations on ship maneuverability in different classic and proposed test maneuvers. Offering essential guidance on the effects of rudders for inland vessel maneuverability, and helping practical engineers make informed design choices, the book is of interest to researchers and academics in the field of naval engineering, as well as students of naval architecture. Industrial practitioners working on ship design may also find it beneficial.

In this work, ship hydrodynamics during inland waterway transport and ship maneuvering are investigated using CFD (Computational Fluid Dynamics) based on OpenFoam. Validation and verification studies are carried out for the mesh convergence, time step convergence, sensitivity to turbulence models and dynamic mesh techniques. A quaternion-based 6DoF motion solver is implemented for the trim and sinkage predictions. Environmental effects on several inland vessels (convoy 1, convoy 2, tanker) are studied using the validated numerical models. Three important aspects, the confinement effect of the waterway, head-on encounter, and ship-bridge pile interaction are simulated. The testing conditions cover a wide range, including various channel dimensions, water depths, ship draughts and speeds. The ship resistance, wave pattern, Kelvin angle and wave elevation at specific positions are investigated as functions of these parameters. Ship maneuvering is investigated using virtual captive model tests based on the MMG (Mathematical Maneuvering Group) model. An actuator disk is implemented to replace the real propeller. Open water test, rudder force test, OTT (Oblique Towing Tank test) and CMT (Circular Motion Test) of a KVLCC2 model are carried out to obtain the hydrodynamic coefficients of the propeller, rudder and ship hull. Using the obtained coefficients, system-based maneuvering simulations are carried out and validated using the free running test data. These studies reproduce real ship tests and thus prove the validity of our numerical models. As a result, the numerical solver is promising in ship hydrodynamics and marine engineering simulations.

A comparison of a high speed container ship using a rudder versus a podded propulsor is made to study replacing a rudder with a pod. A mathematical model is altered to simulate a ship operating with a rudder and with a pod to maneuver. The model incorporates the nonlinear maneuvering equations and couples the surge and sway forces, yaw and roll moment, and the roll angle induced during a steady turn with varying rudder and pod angles. The model uses the hydrodynamic derivatives and coefficients for a high speed container ship. The equations are numerically integrated in order to predict the roll angle, sway and surge velocities, and the ship's position in the xy-plane. Both transient and steady state results are utilized to quantify the relative efficiency of each system. The results are used as a preliminary study into replacing a rudder on a ship with a podded propulsor. The results indicate that the ship responds faster and has a shorter turning radius with the pod at lower initial speeds and pod angles, while the rudder responds better at high speeds regardless of angle. Further research is necessary to study the effects of changing the pod's position and increasing the number of pods used.

Introduction; Overview of problems and approaches; Model test and similarity laws; Full scale tests; Numerical approaches (Computational Fluid Dynamics); Basic equations, Basic techniques; Applications. Propeller Flows: Propeller geometry and other basics, Propeller curves; Numerical methods for propeller design; Lifting line theory; Lifting surface theory; BEM for propellers; Field methods; Cavitation; Experimental approach; Propeller design procedure. Resistance and propulsion: Resistance and propulsion concepts; Interaction between ship and propeller; Decomposition of resistance; Experimental approach; Towing tanks and experimental set up; Resistance test; Method ITTC 1957; Method of Hughes-Prohaska; Propulsion test; Additional resistance under service conditions; Simple design approaches; CFD approaches for steady flow; Wave resistance computations; Viscous flow computations; Problems for fast and unconventional ships. Ship Seakeeping: Introduction to seakeeping; Experimental approaches (model and full-scale); Waves and seaway; Airy waves (harmonic waves of small amplitude); Natural seaway; Wind and seaway; Wave climate; Numerical prediction of ship seakeeping; Overview of computational methods; Strip method; Rankine panel methods; Problems for fast and unconventional ships; Further quantities in regular waves; Ship responses in stationary seaway; Simulation methods; Long-term distributions; Slamming. Manoeuvring: Simulation of manoeuvring with known coefficients; Coordinate systems and definitions; Body forces and manoeuvring motions; Linear motion equations; CFD for manoeuvring; Experimental approaches; Manoeuvring tests for full-scale ships in sea trials; Model tests; Rudders; Computation of body forces; Slender-body theory; Influence of heel; Shallow-water effect; Jet thrusters; Stop manoeuvres. Boundary element methods: Green function formulation; Integral equations; Source elements; Point source; Regular first-order panel; Jensen panel; Higher-order panel; Vortex elements; Dipole elements; Point dipole. Numerical examples for BEM: Two-dimensional body in infinite flow; Theory; Numerical implementation.

This book addresses the principles involved in the design and engineering of planing monohull power boats, with an emphasis on the theoretical fundamentals that readers need in order to be fully functional in marine design and engineering. Author William Vorus focuses on three topics: boat resistance, seaway response, and propulsion and explains the physical principles, mathematical details, and theoretical details that support physical understanding. In particular, he explains the approximations and simplifications in mathematics that lead to success in the applications of planing craft design engineering, and begins with the simplest configuration that embodies the basic physics. He leads readers, step-by-step, through the physical complications that occur, leading to a useful working knowledge of marine design and engineering. Included in the book are a wealth of examples that exemplify some of the most important naval architecture and marine engineering problems that challenge many of today’s engineers.

This book presents various aspects of Ship Manoeuvrability in a form that can be understood without undue effort. Beginning with the equations of motion, the book describes the main manoeuvring mathematical models with their application in the numerical simulation of various manoeuvres. The other topics covered in the book range from manoeuvring model tests and full-scale trials through rudder hydrodynamics and design to manoeuvring standards and guidelines. This book also discusses ship autopilots and dynamic positioning. Finally, it provides a description of unconventional rudders and propulsion devices used for manoeuvring. The book has more than 180 figures to explain various concepts and 40 exercises with partial solutions to confirm that the reader has understood the subject. The book also includes recent developments in the subject and can be a valuable reference for beginners, researchers, and professionals interested in the field.

Fundamentals of Ship Hydrodynamics: Fluid Mechanics, Ship Resistance and Propulsion Lothar Birk, University of New Orleans, USA Bridging the information gap between fluid mechanics and ship hydrodynamics Fundamentals of Ship Hydrodynamics is designed as a textbook for undergraduate education in ship resistance and propulsion. The book provides connections between basic training in calculus and fluid mechanics and the application of hydrodynamics in daily ship design practice. Based on a foundation in fluid mechanics, the origin, use, and limitations of experimental and computational procedures for resistance and propulsion estimates are explained. The book is subdivided into sixty chapters, providing background material for individual lectures. The unabridged treatment of equations and the extensive use of figures and examples enable students to study details at their own pace. Key features: • Covers the range from basic fluid mechanics to applied ship hydrodynamics. • Subdivided into 60 succinct chapters. • In-depth coverage of material enables self-study. • Around 250 figures and tables. Fundamentals of Ship Hydrodynamics is essential reading for students and staff of naval architecture, ocean engineering, and applied physics. The book is also useful for practicing naval architects and engineers who wish to brush up on the basics, prepare for a licensing exam, or expand their knowledge.