, M.Sc. Thesis Sharif University of Technology Ounaghi, Mohammad Safa (Author) ; Abbaspour, Madjid (Supervisor)

Abstract

In order to design a ship with waterjet system, estimation of its hydrodynamic performance is crucial. Presence and operation of waterjet propulsion system changes the flow field and pressure distribution in bottom and stem of ship hull, so affect hydrodynamic performance of craft. In the present thesis, CFD analysis is applied to free surface flow around a waterjet propelled ship using ANSYS CFX software. Also a waterjet propulsion system is built and settled in a ship model and resistance and self propulsion tests are performed. In order to performing a systematic process in project, in the first step, pump design is performed with extracting optimum efficiency relations and cavitation...

Maneuver Modeling and Nonlinear Analysis of a High Speed Ship Considering Thrusting and Propulsive Systems

, M.Sc. Thesis Sharif University of Technology Miraki Baseri, Rahim (Author) ; Sayyadi, Hassan (Supervisor) ; Mehdigholi, Hamid (Co-Advisor)

Abstract

Ship maneuverability is so important from different aspects. According to the regulations of International Maritime Organization (IMO), every vessel has to meet the minimum requirements of mentioned rules. Consequently, prediction of ship maneuverability in early stages of the ship design has become to one of the most necessary steps for shipbuilding and design companies. In this research work maneuvering of a high speed ship has been investigated using three different propulsive modes, considering propeller and rudder systems, azipod propeller and waterjet systems. First of all, hydrodynamics equations of each cases while considering different motion modes such as surge, sway, yaw, and roll...

Design and Construction of Motorized Surfboard

, M.Sc. Thesis Sharif University of Technology Mozaffari, Yousef (Author) ; Khorasanchi, Mahdi (Supervisor)

Abstract

Jetsurf is a recreation vessel at sea. It is a surfboard that is equipped with a motor propulsion system and provides surfing, which is an exciting and popular sport, in calm seas, lakes, dams, rivers and natural and artificial canals. This project is divided into four steps. In the first step, the appropriate dimensions for the design of this device are specified. In the second step, to calculate the resistance of jetsurf, at first a model with similar dimensions including experimental results in Star CCM+ software was validated by computational fluid dynamics method and Overset dynamic mesh technique and then jetsurf resistance with dimensions of 1.8x0.6x0.225 meters was calculated. In the...

Experimental Investigation of Crescent-Shaped Jets in Crossflow

, M.Sc. Thesis Sharif University of Technology Borhani Jahromi, Javad (Author) ; Kebriaee, Azadeh (Supervisor) ; Taiebi Rahni, Mohammad (Co-Supervisor)

Abstract

In this thesis, the physics related to liquid jet injection from injectors with three different crescent-shaped cross-sectional levels into steady and transverse flow were studied. The imaging method in this research was based on shadowgraph, which enables high-speed imaging. With the help of the obtained images, the breakup regimes, including Rayleigh, first and second wind-induced instabilities, were observed for injection into the steady flow. Furthermore, breakup regimes for jet injection into transverse flow, including columnar, columnar-bag, and bag, were also observed. The characteristics of the breakup height in steady flow and the length and height of the breakup along with the jet...