WAVE REFLECTION AND TRANSMISSION IN OPEN CHANNEL TRANSITIONS

The topics are a theoretical development and an experimental investigation of the transformation of water-wave characteristics in the reflection and transmission processes through channel transitions of varying geometry, connecting two prismatic channels of constant cross section. The theoretical developments are based on small amplitude linearized wave theory in an inviscid, homogeneous and incompressible fluid. Two theoretical aspects were treated: (1) The wave amplitude variation in a channel of constant width for a bottom of arbitrary configuration was obtained for the various characteristics of the oncoming waves. Reflection and transmission coefficients were derived for shallow water waves for gradual channel transitions. The experimental part of the report is concerned with the determinations of reflection and transmission coefficients and of the energy relations including dissipation. Experimental relations were also found with regard to wave steepness, a factor which cannot be theoretically dealt with so far in channel transitions. (Author)