Sharif Digital Repository

One of the reducing and controlling tools of high speed crafts is intelligent interceptor. Interceptor is a small blade that is originally installed vertically in stern. This blade creates a high pressure area under hull of the craft and produces lift force and a moment to the bow. The amount of lift force and moment can be changed by controlling the height of the blade. The intelligent interceptor (with automatic change in height of the blade) does the same thing. In this study, structural and software design of intelligent interceptor is done. In software field, optimal and PID controller are designed for interceptor system and the performances are studied in MATLAB SimuLink. The results... 

Ship motion is one of the most complicated problems in hydrodynamics. These motions accompany with non linear phenomena and their modeling is very difficult. Analytical solution for governing equations for such problems is not possible and experimental study is very expensive. In this state we need remarkable time for investigating of influences of environmental condition changes. In previous research done by Jahanbakhsh and Panahi,a software created that could solve fluid domain and rigid body equations. But the software needs to be developed in some aspects. Aim of this research is expanding of rigid body motion section of software. The software is capable of getting force or moment and... 

Interceptor is a blade installed on planing hull transom, and it helps the planing performance by making an stagnation point on aft part of the hull thus generating a lift force and reducing the planing trim. In the present study a numerical modeling of a planing hull in still water has been made and the effect of an interceptor in the numerical model has been studied. Then by validating the model with and without the interceptor through experimental model testing, it has been used for modeling a planing hull in waves with an interceptor. The numerical modeling has been made using 2DOF analysis in Ansys-CFX and the experimental model tests have been done in Mechanical department of Sharif... 

In recent years, planing boats have been used in more exposed areas, for instance as patrol boats, pilot boats, coast guard and small naval vessels. When such a small vessel operating in a rough-water environment, frequently experiences violent motions and vertical acceleration. Even on calm water, porpoising may occur and may be severe as the speed is increased. Operation of the crew, equipments and overall operability of the vessel always suffer from mentioned motions. In the present study, the impact of fixed and controlled interceptors on a planing crafts hydrodynamic and seakeeping quality is investigated through application of an experimental and theoretical methods. Two scaled-down... 

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 research, a cooperative terminal guidance algorithm has been derived for simultaneous multi-interceptor collision with a target. This algorithm is obtained using the combination of model predictive control method and differential game theory. One of the features of this method is the calculation of the optimal guidance command in the form of an explicit relationship. Another feature of this method is its resistance to disturbances due to the use of differential game theory. The first innovation of this research is the use of this hybrid method to create a guidance algorithm, even in the non-cooperative guidance problem. The next innovation is in creating a cooperative terminal...