Numerical modelling, experimental verification and performance analysis of wave energy converter

Large amounts of power exist in the oceans in the form of wave energy. Many devices have been proposed for getting energy from waves. For the extraction of large amounts of power, offshore conversion is desirable. WEPTOS WEC developed on the famous concept of salter duck, employs a well-known and effective method in order to extract wave energy. It consists of series of nodding Ducks. The idea of nodding duck was primarily proposed by the famous scientist Salter Duck in 1974. Experimental modelling cost an extraordinary amount of cost in testing and changing a single parameter requires an additional cost. Also, good testing facilities are not available everywhere, and this introduce an additional shipping cost as well. Numerical modeling is the cheapest and quickest way of learning about a device (energy output, loads, behavior). It provides an easier way to optimize the system by changing various parameters to attain an optimal power output. This present work represents the steps carried out to develop a successful numerical model of a single rotor majorly by the use of ANSYS AQWA. The methods for overcoming the limitations with software are derived and presented as well. Numerical models in frequency and time domains are made. Step by step the non-linearities are introduced in time domain model to carefully address the effect of each non-linearity in model. The Numerical Model has been compared at various steps with the experiments done at Aalborg University, Denmark. A constant coulomb force PTO has been used in the model for evaluating the power absorbed. On the basis, of this non-dimensional efficiency has been evaluated for single rotor. The rotors efficiency has been evaluated for the different configurations. An analysis on the performance of WEPTOS due to multi-body interaction is a part of this work as well.