The Surf Statistical Model On The Fringing Reefs Based On Fume Experiments And Numerical Simulation

In recent years,more and more coastal structures and military activities have been carried out on islands and coral reefs.The wave propagation on the reefs and the infragravity waves produced by the wave breaking on the reef flat have a great influence on the reef buildings,the beach erosion and the navigation of the ships.The propagation characteristics of waves on coral reefs have become the focus of nearshore hydrodynamics research.In this paper,the physical and numerical simulations on wave shoaling and breaking have been conducted and the statistical model of breaking height has been built.Firstly,the research on the influence of the value of slope on wave breaking height has been made by the simulation and statistical analysis from the mild slope to the steep slope.The results show that when the slope is less than 1:12,the breaking height increases with the increase of the slope;when the slope is greater than or equal to 1:12,the slope has little influence on the breaking height.Secondly,a fume experiment is conducted with 1:2 and 1:3.86 fore-reef slope respectively.The wave propagation characteristics on reef are analyzed and the existing breaker criteria are discussed.The wave conditions that can be conducted in the flume are limited.Therefore,numerical simulations are also carried out in this paper.Based on FUNWAVE-TVD model,the model results are verified against the laboratory data of this paper.Then the numerical simulations of the surf on actual scale with 1:4,1:8 and 1:12 fore-reef slope respectively are carried out in order to make up the lack of the wave height data on complex wave conditions.Finally,based on the above physical and numerical simulation results,the existing statistical models of breaking height are checked and the limitations of the models are analyzed.A new sectional calculation model on the reef has been built.The new model has a considerable effect on the calculation of the surf on the topography including steep slope and reef.This paper has also conducted some numerical simulations on infragravity waves based on FUNWAVE-TVD model and NHWAVE model.The results by the two models are compared and the characteristics of infragravity waves on different conditions are discussed.Along with the military activities being carried out in the South China Sea,it is necessary to make an accurate forecast on surf breaking on reef.The results of this study can provide data and references for the surf forecast and numerical simulation on coral reefs.