On short-crested waves: experimental and analytical investigations

Analytical and experimental investigations were conducted on short-crested wave fields generated by a sea-wall reflection of an incident plane wave. A perturbation method was used to compute analytically the solution of the b asic equations up to the sixth order for capillary-gravity waves in finite depth, and up to the ninth order for gravity waves in deep water. For the e xperiments, we developed a new video-optical tool to measure the full three dimensional wave field eta(x, y, t). A good agreement was found between th eory and experiments. The spatio-temporal bi-orthogonal decomposition techn ique was used to exhibit the periodic and progressive properties of the sho rt-crested wave field. (C) 1999 Editions scientifiques et medicales Elsevie r SAS.