GENERATION OF NONLINEAR RANDOM WAVES WITH BOTTOM WAVE MAKER USING EXTENDED BOUSSINESQ EQUATIONS: EFFICIENT METHOD TO ABSORB REFLECTED WAVE ENERGY

When waves are generated in a flume by the conventional piston or flap wave maker, waves reflected from structures will arrive at the wave maker and experience re-reflection. These re-reflected waves will propagate to the structures so that the target wave energy cannot be accurately obtained. Since 1980s, methods of internally generating waves inside a computational domain and putting sponge layers at the domain end have been developed in numerical modelling. Internally generated waves will propagate both directions from the wave generation zone and waves reflected from the structures will pass through the wave generation zone without any reflection by the wave maker and be absorbed in the sponge layers. Jung et al. (2023) developed linear wave makers in a flume which have paddles moving up and down from the bottom.