Stephan T. Grilli and Ib A. Svendsen and R. Subramanya
Associate Professor Professor
Graduate
student
Department of Ocean Eng.
Department of Civil Eng.
niversity of Rhode Island
University of Delaware
Narragansett, RI 02882, USA
Newark,
DE 19716, USA
Abstract :
Shoaling and breaking of solitary waves is computed on slopes
1:100 to 1:8 using an experimentally validated fully nonlinear wave model
based on potential flow equations. Characteristics of waves are computed
at and beyond the breaking point, and geometric self-similarities of breakers
are discussed as a function of wave height and bottom slope. No wave breaks
for slopes steeper than 12 deg. A breaking criterion is derived for milder
slopes, based on values of a nondimensional slope parameter So.
This criterion predicts both whether waves will break or not and which
type of breaking will occur (spilling, plunging, or surging). Empirical
expressions for the breaking index and for the depth and celerity at breaking
are derived based on computations. All results agree well with laboratory
experiments. The NSW equations fail to predict these results with sufficient
accuracy at the breaking point. Pre-breaking shoaling rates follow a more
complex path than previously realized. Post-breaking behaviors exhibit
a rapid (non-dissipative) decay, also observed in experiments, associated
with a transfer of potential energy into kinetic energy. Wave celerity
decreases in this zone of rapid decay.
Keywords :
Solitary wave propagation; wave shoaling; wave breaking; wave runup on beaches; long wave theory; fully nonlinear waves; experimental modeling of waves; numerical modeling of waves; boundary element method.