Numerical simulation and experimental investigation on performance of the wells turbine in irregular oscillating flow

The Wells turbine is an axial-flow air-turbine designed to extract energy f rom ocean waves. An important consideration is the self-starting capability of the Wells turbine, a phenomenon encountered where the turbine accelerat e by itself up to a certain speed for the best turbine performance. In orde r to clarify the self-starting characteristic and running performance of th e Wells turbine in an irregular oscillating flow, a numerical simulation pr ocess is established in this paper on the rational assumption of quasi-stea dy flow conditions, Both self-starting characteristics and running performa nce are obtained through the numerical simulation and subsequently compared with the experimental data achieved on a computer-controlled oscillating f low test rig which could realize some irregular oscillating flow according to the specified spectrum. Results show that the self-starting time decreas es with the increase of the significant wave height and the mean frequency of the irregular oscillating flow, Therefore, it is possible to predict acc urately the performance of the Wells turbine by computer simulation.