Experimental study on inflatable circular diaphragms used in the oscillating water column wave energy converter

Wave Energy Converters (WECs) convert ocean waves' kinetic and potential energy into electricity. This paper studies the effect of different parameters on an Inflatable Circular Diaphragm (ICD) used in a WEC de-vice. A small-scale Oscillating Water Column (OWC) with an elastomer part at the top of the air chamber is considered, and several experiments on the water tank and dry test rig are conducted. In the first part, the experimental results of an OWC with an ICD in the small water tank are presented, and the effect of wave height and frequency on the deformation of an elastomer is studied. In the second part, further experiments are done in a dry test rig to analyse a stiffer elastomer. Some parameters' effects under harmonic and static loadings are investigated. Also, the experimental results are validated using finite element-based software, and numerical simulations are in excellent agreement with the Qualisys system's results.