Ahmad Reza Kohansal

n recent decades, speedboats have become extremely important and various hull shapes have been proposed, designed and built to achieve high speeds. High-speed vessels are divided into four groups: single-hull, hydrophilic, surface-effect and multi-hull vessels. Here, the main focus is on the wave piercing vessel with spray rail. Speedboats face various challenges to reach the high speeds intended by the designer. V-shaped transverse vessels do not generate hydrodynamic lifting force well. One way to create a hydrodynamic lifting force in fast vessels is to add a spray rail in the longitudinal direction of the hull. When water flows to the side of the float, the water flow is directed downwards using a spray rail, causing a hydrodynamic lifting force. In this dissertation, with the laboratory analysis of the wave piercing vessel, which includes trim, resistance and displacement of the height of the center of gravity (VCG) of vessel, once in calm water conditions with spray rail at a location of 24%T and once without installing spray rail, it has been compared by numerical analysis under exactly the same conditions, which has an acceptable error rate. This optimization, which is done by applying spray rail, significantly reduces trim and resistance at high speeds, as well as increasing center of gravity height changes. This dissertation can be a reliable reference for improving the performance of planning body vessels in the future