![]() Laboratory data on breaking wave height employed in this paper have been compiled from various sources, as summarized in Table 1. On the basis of this comparison, a new semiempirical formula is proposed involving the beach slope and the offshore wave steepness that displays improved behavior and agreement with the data. In this paper, we compare six existing formulas for calculating γ b, with an extensive data set. Because these formulas are semiempirical and often based on a limited data set, their accuracy over large data ranges might not be so good. Rattanapitikon and Shibayama (2000) compared many existing formulas and showed that they differed significantly and induced large uncertainties when slopes deviated from the typical range ( i.e., m 0.1). Where m is the slope of the beach and λ ∞ = H ∞/ L ∞ is the deep-water (offshore) wave steepness ( H ∞ and L ∞ are, respectively, the deep-water wave height and wavelength).Ī simple way to estimate the location of the breaker line is to compute the wave height-to-water depth ratio where the wave will break (breaker depth index γ b), which seems, according to different authors ( Galvin, 1972 Goda, 1970 Miche, 1944 Weggel, 1972), to be a function mainly of the offshore wave steepness and the mean beach slope. Also, a discussion is included on the application of the formula to random waves and on the relationship between the breaker depth index and the Irribaren number to distinguish between different breaker types. A new formula is proposed to predict the breaker depth index with the best possible accuracy. It was found that most formulas show quite good predictions for cases including gentle slopes (0.01 0.1), and the formulas do not always present a physically correct behavior with respect to the two main parameters. The behavior of these formulas was studied with respect to the main governing parameters, which are the beach slope and the deep-water wave steepness. The applicability of six existing formulas for computing the breaker depth index was examined with the use of a large amount of published laboratory data (524 cases collected from 22 sources). This study was undertaken to establish the most reliable breaker depth index formula that will yield satisfactory predictions for a wide range of hydraulic and beach conditions. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |