Sharif Digital Repository

Performing research and development in the field of modern vessel types which serve several functions is considerably necessary because of their importance and rapid development. HARTH vessel is considered one of the important ships which has been recently attracted much attention from the world. In this respect, a full investigation of its performance could make a big contribution to its optimum design and appropriate exploitation.“HARTH” ship is the abbreviation for “High Aspect Ratio Twin Hull” is included in the catamaran vessel category with a high aspect ratio with respect to their underwater cross-section’s ratio of length to width.A host of crucial issues should be considered for... 

Increasing the speed of marine transportation services for specific mission and rapidly movement of persons or product always have been considered major issue in maritime industry. In recent years different technology have been used by high speed vessels manufacturer for increasing the safety of crew and passengers at sea. Catamaran is one of the most important high speed craft in marine transportation industry. High speed catamaran nonlinear behavior in high velocity is causing longitudinal instability and large motions. Active control surfaces like hydrofoil and interceptor can be used for reducing high speed catamaran motions in waves. This control surfaces react an adequate action... 

The purpose of this study is extracting a dynamic model of longitudinal motions of high speed catamaran in regular and irregular waves, and then motion control of vessels by using of foil control elements and interceptor. For simulating longitudinal motions in regular waves, at first the longitudinal hydrodynamic coefficients of vessels should be extracted, then by substituting extracted coefficients in cumminz equation and using system identification methods, some equations are presented to estimate longitudinal two degree of freedom motions of high speed catamaran in waves. In this thesis the extraction of hydrodynamic coefficients is based on both numerical and experimental methods. ANSYS... 

In this thesis, an attempt is made to provide a hydro-aerodynamic mathematical model of a 20-bird batboat with a combined wing with catamaran body shape equipped with a parachute propulsion system in the rising phase of the surface and optimizing the propulsion system to reduce the take-off phase of the bird's boat. For this purpose, the hydro-aerodynamic modeling of the bird's boat from the rest period to the cruise phase has been considered, taking into account the parachuting system. For this purpose, three methods are considered. In the first method, combinatorial wing aerodynamic modeling and hydrodynamic modeling of the radar catamaran float were first studied. Finally, in the case of... 

In recent years design and manufacturing of high speed marine vessels has been developed. to estimate and control dynamics of these vessels the dynamic equation is needed.The aim of this research is Determination of hydrodynamic and aerodynamic coefficients and longitudinal dynamic equation of a high speed catamaran wich is a kind of AAMV. There are three ways to determine these coefficients. Analytical method which is usually not applicable for industrial problems, Experimental method which is too expensive and numerical method which have two parts. The first is softwares that analyse the flow with assumption that the fluid is inviscid and second softwares which solve the full Navier-Stokes... 

Dynamics modeling of high speed crafts in waves is one of the major problems in design precess. Mathematical models compared with other methods have lower cost for studying behavior of ships in waves. On the other hand, experimental methods may also be suitable for various problems. Due to nonlinear behavior of high speed crafts, dynamics modeling of these vessels will be. Combination of experimental and mathematical models to predict the precise dynamics of high speed craft in wave is a suitable method. In this study, a nonlinear method is used for predicting the motions of vessels in waves. In this method, nonlinear time domain behavior of vessel is studied. At first a monohull vessel... 

Properly adjusting the trim angle during the craft speed up will be extremely important in special cases as in sport competitions or military missions. In such applications, the goal of trim adjustment is to reach final speed in a minimum possible time which is an advantage to just passing the resistance hump. Present study tries to provide insight into how the concerned control variables such as angles of the drive system and trim tab of a planing craft should be changed during acceleration mode so as to minimize the time needed to reach the final speed. This is a time-optimal control problem. Optimal control theory has been used previously for the motion control of marine vessels in... 

The current research is one of the sections of the project for the design and construction of an Unmanned Surface vehicle (USV) , with the goal of extracting the dynamic model of the float using experimental tests. Initially, a literature review on system identification methods and the development of a dynamic model of the float has been conducted. Following that, the process of constructing and equipping a Catamaran platform for conducting tests and collecting suitable data for extracting the dynamic model has been described. Subsequently, tests have been conducted on the constructed float.Using the data obtained from the experimental tests, an artificial neural network has been employed to...