Modeling of an ocean waves power device AWS

Abstract

AbsfracC This paper describes the steps for building the time domain model of an ocean waves energy converter device called AWS. This model will be useful for the design of such devices and for the prediction of its behavior in different sea conditions. Besides the inherent complexity associated to the nonlinear dynamics of the AWS components, for time domain simulation, a convolution integral is conventionally used to model the hydrodynamic diffraction and radiation forces, being the last one characterized in the frequency domain by the added mass and damping. However, this integral is relatively expensive to evaluate and difficult to use with efficient integration routines.Here an efficient methodology mixing frequency and timedomain is introduced to deal with this problem. The wave transfer functions were first obtained from a numerical finite element code, as vectors containing the frequency response of the desired transfer functions. The data obtained is then used to identify the corresponding analytic form of the transfer functions, which is integrated in the time-domain model. The model includes the slow and fast dynamics of the AWS behavior.

Numerical simulation of a submerged wave energy converter under irregular wave conditions

“…The chamber enclosed inside both cylinders is filled with pressurized air (see Figure 1). Although different in their design, the generic model of the TWED bears some resemblance to that of the Arquimedes Wave Swing (AWS) [8]. When a wave crest passes over the TWED, the pressure outside the floater increases, pushing it down and increasing at the same time the air pressure in the chamber.…”

“…An example of this type of WEC is the Wave Dragon (Wave Dragon ApS) [7]. In this paper, the performance for one irregular wave case of a submerged point absorber similar to the AWS [8] is analysed using a non-linear time domain numerical model like the one described in [9]. The purpose of the article is to apply this kind of model to the optimization of the Power Take Off (PTO) damping constant in order to achieve a maximum energy absorption during the TWED life cycle under a given wave climate.…”

Extended kalman filter based incident wave estimation in point absorber

“…Detail explanations are presented in [4] To deduce the exact motion of the PA WEC and solve the Eq. (1), a numerical method such as finite element method are applied because the Eq.…”

Estimation of incident wave of AWS-based wave energy converter using extended Kalman filter

“…As described above, the A WS WEC is installed on the seabed. Therefore the deep water incident wave potential under the regular wave environment is expressed as follows: (9) Since the shape of the lid is circular and symmetric, we can assume that the force is acting only in the z-direction. Then the force per unit length in the z-direction is derived using (6) and (7) and is given by…”