Numerical and Experimental Modelling of WECs

Abstract

[Discussion] In this chapter the importance of numerical and experimental modelling when de- veloping a wave energy converter was emphasised. Each section could be ex- panded into a single chapter, but given the scope of this book the main objective is to provide a starting point for those who are novices to the wave energy field. In 5.1, frequency domain modelling is presented at the expense its time domain equivalent. This is due to the number of applications using both approaches and to the ease-of-use that frequency domain tools provide. In addition, the number of numerical models which directly implement solutions of the Navier-Stokes equa- tions are still a rarity, but their use could increase in the near future. A good start- ing point for those interested in the field is given in the review conducted by McCabe (2004). Section 5.2 gives insight to both tank and wavemaker design. The different op- tions that allow the accurate simulation of both shallow and deep water waves are detailed. The influences of geometrical parameters like tank width and paddle size were also studied, and considerations regarding the absorption of reflected waves were presented. Section 5.3 is intrinsically linked with 5.2 as it provided generic guidelines for the use of experimental facilities. Continuous validation of numerical simulation by means of experiments in wave tanks is essential and it is fundamental that such notion is clear to both developers and researchers. Finally, section 5.4 demonstrated the integration of numerical and experimental modelling programmes in a commercial environment, by exemplifying the pro- gress made when developing the Pelamis WEC. Several stages that eventually lead to a full-scale prototype were described.