An experiment on harbour resonance induced by incident regular waves and irregular short waves

It is generally accepted that bound long waves generated by wind waves excite harbour resonance. Nevertheless it is not clear if there are differences in the harbour response when resonance is induced by incident regular free long waves or by incident bound long waves. This experimental investigation aims at determining these differences for a narrow long bay. The finite water depth inside and outside the narrow bay is constant. For incident bound long waves, two cases have been studied: in the first case bound long waves are generated by carrier bichromatic short waves which form regular wave groups; in the second case bound long waves are generated by irregular short waves. The experimental setup allows the characteristics of the forcing waves to be defined with a good degree of accuracy. The bay response is obtained for the three cases of regular free long waves and bound long waves for regular and irregular groups.