Research
Power Integrity Requirement of New Generation of ROV for Deep Sea Operation
Remotely operated vehicles (ROVs) system requires powerful vehicles to support the bollard thrust and tool power required for deepwater tasks. Evolving deeper waters, vehicle support for heavy-duty tasks demand, deepwater subsea construction, repair and maintenance require efficient ROV power pack to support these tasks. Typical work-class ROV systems provide maximum power levels ranging from 100 to 200 horsepower that produce impressive thrust in either vertical or horizontal directions. Problem associated with ROV power pack include inefficiencies in the power system designs that limit peak system performance thrust curves, inability of the hydraulic system to adjust to varying demands, environmental concern related to energy usage and ship husbandry. This paper address the design and development of a variable pressure power delivery and propulsion system that significantly increases overall system efficiency to maximize use of available power.
CFD Simulation for Cavitation of Propeller Blade
Propeller cavitation is a major problem in ship operation and the costs of repair and maintenance is high for ship-owners. Proper design of propeller plays a very important role in life cycle and the performance of a vessel. The use of simulation to observe various parameters that affect cavitations can be helpful to optimize propeller performance. This project designs and simulates cavitations flow of a Kaplan series, Fixed Pitch Propeller (FPP) of a 48-metres Multipurpose Deck Ship at 11 knots. Simulation test was carried out for laminar and turbulent flow using Computational Fluid Dynamics (CFD) approach to observe cavitations occurrence at selected radius. The parameters considered are pitch angle, angle of attack, viscosity of sea water, operating vapour pressure in the sea water, engine power, lift and drag vectors of each of the blade sections, and resultant velocity of the fluid flow. Comparison of performance is made and it compares well with the theory. Thrust coefficient (KT), torque coefficient (KQ), thrust (T), advance coefficient (J), and cavitations number (ΓΖ), were calculated to deduce efficiency and validate the model. The study can be used to build a prototype physical model that could be beneficial for future additional experimentation investigation.
Ship Structural Integrity of Aluminium Stiffener Panel for Consequence Reduction
The aluminium stiffener panels in ship structure are paramount to ensure safety and to guarantee the structural strength and integrity of the ship. The aluminium stiffener panel is very important to ship building, especially when the ship faces collision or unstabilized structure; the aluminium stiffener panel tends to increase bending moment, vertical shear force and stresses. This study investigate the strength of the aluminium stiffener panel at the amidship bulkhead with different shapes and typesin order to determine the strength of the aluminium stiffener from its features. AA 5083-H116 aluminium stiffener panel used has been approved by the recognized organization for shipbuilding. The aluminium stiffener panel has been tested using bending moment test and compressive load to obtain the highest endurance. Three types of aluminium stiffener panels, which are a flat shaped, L-shaped and T-shaped panel, are used in order to obtain the best panel ability for a better ship structural system. The aluminium stiffener panel is tested at the area where it is different to determine area where they are affected by extreme heat due to the welding results and fabrication. The result has showed that the aluminium stiffener panel in shipbuilding process effect in an area without extreme heat is more stable.
