Technology Research Of Multi-scale Wave Numerical Modeling

Wave is one of the most important factors of the marine environment, so the accurate simulation of wave farm is very important for practical engineering. However, there is yet one wave model can simulate wind wave generation, wave transmission, even to wave breaking till the shore accurately. The theoretical researches and applications of wave models are reviewed in brief. The advantages and disadvantages of kinds of wave models are compared, analyzed and discussed. The third generation wave model SWAN and shallow water equation model SWASH are used to simulate wave farm of from China East Sea(ECS) to Yangtze River Estuary water area with nested method.Some works have been done to build the multi-scale wave numerical modeling of Yangtze River Estuary area.First of all, the third generation wave model SWAN is used to simulate the wave climate of Yangtze River Estuary area. Triple nested calculation is earried out during the simulation of the wave farm of Yangtze River Estuary area. Wind data and tide data are essential to set up wave model. The wind data used in this paper is calculated by WRF model which is verified with the measured data. And the tide data is calculated by Delft3D-FLOW model, the water level boundary of tide model is obtained from Japanese astronomical model NAO.99b through nested method. The water level of this tide model is validated by measured data of tide stations. The validated wind data and tide data are used to drive the wave model. Niupijiao and Nancaodong are selected to validate the wave model. The result shows that the simulated wave height and wave period agree well with the measured data, indicating that the self-nested calculation of SWAN model can simulated wave farm of Yangtze River area accurately.Then, non-linear shallow water equation model SWASH is used to simulate wave around the Hengsha promoting silting enclosure of Yangtze River Estuary. The boundary of SWASH model is the wave spectrums calculated by SWAN model. And the wave model is validated through comparing with measured data. It shows that the calculated wave agree well with the measured wave.At last, the nested method of SWASH model is used to simulate wave transformation in one-dimensional mode, the results indicate that the 1D model can describe the wave transmission precisely.This paper applies SWAN model and SWASH model to simulate wave farm of Yangtze River Estuary area through above steps, building a new method of wave numerical simulation. The characters of wave distribution are discussed in detail for ECS, Yangtze River adjacent sea, Estuary area and local project area for the 2013 year, and the wave roses are given seasonally.Multi-scale wave numerical modeling is set up in this paper, the application in Yangtze River Estuary area as an example. Wave generation, wave transmission and wave breaking are taken into account in this numerical modeling method. Meanwhile, the influence of tide and current on wave is taken into account. A wave-current coupled model is built up in this paper. The nested run of SWAN and SWASH model is proved to be reasonably, it can provide reference for engineering and academic research.