Breaker type classification on three laboratory beaches

TLDR

Breaker type for waves on smooth concrete slopes depends on beach slope, wave period, and either deep‑water or breaker height. Breaker type is classified using two dimensionless parameters—offshore H0/(L0 m²) and inshore Hb/(g m T²)—with deep‑water heights derived from linear wave‑generator theory and data collected from films of dominant breakers. As the offshore or inshore parameter increases, breaker type progresses from surging/collapsing to plunging to spilling, with surge‑plunge thresholds near 0.09 and 0.003 and plunge‑spill thresholds near 4.8 and 0.068, respectively.

Abstract

Breaker type, for waves on smooth concrete slopes, depends on beach slope m, wave period T, and either deep-water or breaker height, H0 or Hb. For forty-three varied laboratory conditions, breaker type can be sorted fairly well by either of two dimensionless combinations of these variables, an offshore parameter, H0/(L0m2) or an inshore parameter, Hb/(gmT2). As either of these parameters increases, breaker type changes from surging or collapsing to plunging to spilling. For the offshore and inshore parameters, respectively, the surge-plunge transition values are about 0.09 and 0.003 and the plunge-spill transition values are about 4.8 and 0.068. The deep-water heights in the offshore parameter were computed from linear, wave-generator theory. Breaker type data were obtained from films of breaking waves for conditions that produced a dominant breaker type, free from interference by secondary waves.