Scale effects in physical modelling of a generalized OWC

Natural oscillation period is analysed first, which is obtained from the delay between the oscillating motions inside the device and those outer the front wall. Such a period increases in the small scale with the height of the chamber due to the “spring” effect of the air compressibility. Furthermore, the downscale of the OWC causes a reduction of the reflection coefficient, which is in part recovered by increasing the height of the device. Extreme loadings on the front wall can be underestimated by the small scale but safe conditions are always achieved for the high-chamber model.