Research On Numberical Simulation Wave In Bohai Bay By SWAN Model

The ocean wave is a major marine disaster, it is vital important and significancethat researching wave development, grow and real-time numerical prediction to thefishery fishing, sea transportation and construction and sea military activities, etc.This article utilizes third generation shallow ocean waves pattern SWAN40.84(Simulating Waves Nearshore),as well as high-precision mesoscale atmosphericmodel WRF (Weather Research and forecast) numerical pattern predicting windfarms,builds and verifys SWAN model which is suitable to simulate bohai bay wave.We separately study linearity growth and the exponential growth of inputtingwind by choosing two weather process from WRF model basing on wind stresscalculation method.The research show that we should consider the linear growth itemin the SWAN pattern.For three exponential expressions of wind input and correspondsto white waves breaking expression in SWAN pattern,we design portfolio,Komenprogramme,Janssen programme and Westhuysen programmes,to research the SWANmodel applicability in simulating Bohai bay wave under difference combinationprogrammes.we compare simulation results of three portfolio with measured data，theresult shows that average period of three programs are relatively small，howerer，significant wave height of simulation is close to measured datd. Westhuysen saturatedthreshold program scenario simulations work best in statistical analysis of thesimulation result.We modifiy wind stress drag coefficient and water depth–induce breakcoefficient in westhuysen form to improve wave simulation accuracy under WRFwind pattern. Finally,we design the swan-swan three levels self-nesting methods tosimulate Bohai Bay wave, and validate simulation results, wave height and period,agree better with the measured data than before,This confirm the establishedmathematical model SWAN is suitable to wave forecsting in Bohai bay.