NONLINEAR WAVE MAKER IN A CHANNEL OPERATING AT CUT-OFF FREQUENCIES: THEORY AND EXPERIMENT.

Experimental and theoretical studies of sloshing waves in a rectangular channel at the vicinity of second cut-off frequency are presented in this paper. The experiments were performed in a wave tank which is 1. 2m wide, 18m long and 0. 9m deep. Sloshing waves were generated by a computer-controlled segmented wavemaker consisting of four independent modules. Experimental results are compared with numerical solutions of the appropriate nonlinear Schroedinger equation, a derivation of which is also presented. The importance of dissipation effects on the physical processes of wave evolution is discussed, and a simple dissipative model is suggested and incorporated in the governing equations.