Pressure variation within a semi-submerged chamber caused by surface waves

The hydrodynamic performance of a two-dimensional model of an oscillating water column (OWC) device capable of transferring wave energy to electricity is analyzed within the framework of the linearized water wave theory. Unlike traditional OWC devices with a fully rigid front wall, our model contains an elastic segment modeled as a thin elastic plate, while the remaining front wall remains rigid. The boundary value problem is formulated using the eigenfunction expansion method in each fluid sub-domain, and the equations are solved employing the least squares method. The radiation susceptance, radiation conductance, and maximum hydrodynamic efficiency are evaluated for elastic portion parameters, including length, center position, and flexural rigidity, as well as the chamber width and front wall draft. Velocity profiles at selected frequencies are presented to illustrate fluid behavior at spike and resonance frequencies. A comparison of extracted power and hydrodynamic forces between the elastic and rigid OWC configurations indicates that the elastic device can achieve higher power output at moderate to high frequencies, with relative improvements of approximately 3 times the power of the rigid OWC. Additionally, the hydrodynamic loading on the front wall with respect to the rigid OWC remains within ( 1 – 2 ) % across all configurations considered, confirming that partial elasticity enhances energy capture without compromising structural integrity.