The Research On The Hydrodynamic Performance Of Wave Energy Propelled Unmanned Observation Catamaran

Wave energy can be used as one of the most sustainable utilization and renewable energy, which have already attracted many scholars to pay close attention to it. It caused us to think deeply that, how to accelerate the development of equipment on clean energy research, how to improve the utilization of wave energy efficiency. In this paper, the design of the wave energy propelled unmanned observation catamaran system, which is a multi-function Unmanned Surface Vehicle(USV), combining of both utilization of wave energy, and collection of marine monitoring data. We selected the catamaran hull which has two elongated piece-bodies, and installing two symmetrical swinging hydrofoil in the head and tail of the hull. The research on the hydrodynamic performance of wave energy propelled unmanned observation catamaran is divided into three parts. First, it is the study of hydrostatic resistance performance. Second, it is the frequency domain response analysis of the USV system. In the last, it is the motion characteristics analysis about the hydrofoil. A 1: 1 model boat was used to measure the hydrostatic resistance by towing tank experiments. Than, using 1957 ITTC formula and Taylor-Gertler method to approximately estimate hydrostatic resistance for the system, and using CFD software to calculate the resistance. But the latter two results are small comparing to the results of experiments. After comparing the calculation resistance of three numerical models whose spacing between two piece-bodies are K = ∞, K = 0.4125 m and K = 0.825 m, found that the interaction of spacing does have some impact on the resistance. This paper also compared the the added mass, radiation damping and RAOs on the six dof between the system with foil and without foil. Those foils do have an influence on added mass and RAOs in the direction of swing, pitch and heave, which made the rerults bigger than that system without foil. But radiation damping has been less affected by the hydrofoil. Finally, we using the dynamic mesh module in FLUENT software, simulated the motion of head hydrofoil in a different wave cycle, analyzing the thrust performance and utilization rate in the wave. Successfully simulate the movements of head foil and tail foil in the same time, analyzing the thrust performance and utilization rate in the wave between the two hydrofoils.