INTERNAL VELOCITIES IB THE UPRUSH AND BACKWASH ZONE

[摘要] In an earlier paper the authors reported the results of both field and hydraulic model investigations into the reaction of beaches to the action of waves of low phase difference. These waves are those whose time of uprush on the beach is equal to or less than 0.7 T, where T is the wave period. The present paper summarises the study of the internal velocity field under similar conditions. By making certain simplifying assumptions based on observations of the profile of the wave during uprush and backwash, the surging wave is open to quantitative description. For very low phase differences the uprush is approximately the reverse of the backwash, but to a different time scale. However, as the phase difference approaches the limit for the surging condition, the uprush starts and may remain in the form of a bore.

[学科分类] 建筑学

[关键词] uprush zone;backwash zone;internal velocity;velocity