What specific hydrodynamic phenomenon is exploited by oscillating water column (OWC) WECs?

Oscillating Water Column (OWC) Wave Energy Converters (WECs) exploit the hydrodynamic phenomenon of wave-induced air pressure oscillations within a chamber. An OWC device typically consists of a partially submerged, hollow structure open to the sea below the waterline. As waves enter the chamber, they cause the water level inside to rise and fall. This rising and falling water column acts like a piston, compressing and decompressing the air trapped above it within the chamber. The oscillating airflow is then channeled through a turbine, typically a Wells turbine or an impulse turbine, which rotates and drives a generator to produce electricity. The key hydrodynamic principle is therefore the efficient transfer of wave energy into oscillating air pressure within a confined space, converting the wave's vertical motion into a usable pneumatic (air-based) power source. The dimensions and geometry of the chamber are carefully designed to maximize this air pressure oscillation for optimal energy capture.