LABORATORY TESTS OF PERMEABLE WAVE ABSORBERS

Laboratory studies involving surface waves usually require the use of absorbers at some boundaries of the test facility to prevent objectionable reflections of the test waves. Such absorbers frequently consist of sloping beaches with or without a layer of permeable material. These are sometimes used in conjunction with other devices which absorb part of the wave energy. If sufficient space is available, a long absorber with a low surface slope can be used, resulting in very low reflections. However, space limitations sometimes necessitate the use of an absorber of minimum length with a steeper surface slope. In such cases permeable materials are highly beneficial to assist in absorbing the wave energy.