An application of Boussinesq equations to Bragg reflection.pdf

ARTICLE IN PRESS0029-8018/$ - see doi:10.1016/j.oc Correspondi E-mail addreOcean Engineering 34 (2007) 870–883 /locate/oceanengAn application of Boussinesq equations to Bragg reflection of irregular waves Tai-Wen Hsua,, Shih-Chun Hsiaob, Shan-Hwei Ouc, Swun-Kwang Wangd, Bin-Da Yange, Shih-En Choua aDepartment of Hydraulic and Ocean Engineering, National Cheng Kung University, Tainan 701, Taiwan bDepartment of Marine Environmental Informatics, National Taiwan Ocean University, Keelung 202, Taiwan cDepartment of Environmental Engineering and Sciences, Tajen University, Pingtung 907, Taiwan dDepartment of Safety, Health and Environment Engineering, Chung Hwa College of Medical Technology, Rende 717, Taiwan eDepartment of Information Management, Hsing Kuo University of Management, Tainan 709, Taiwan Received 12 September 2005; accepted 22 February 2006 Available online 30 June 2006Abstract A numerical model based on the second-order fully nonlinear Boussinesq equations of Wei et al. [1995. Journal of Waterway, Port, Coastal and Ocean Engineering 121 (5), 251-263] is developed to simulate the Bragg reflection of both regular and irregular surface waves scattered by submerged bars. Particularly for incident regular waves, the computed results are observed to agree very well with the existing experimental data as presented by Davies and Heathershaw [1984. Journal of Fluid Mechanics 144, 419-446] and Kirby and Anton [1990. Proceedings of the 22nd International Conference on Coastal Engineering, ASCE, New York, pp. 757–768). In the case of incident irregular waves, the simulated results reveal that the distribution of Bragg reflection from irregular waves becomes more flat than that of regular waves. Due to lack of experimental data, the numerical results for incident irregular waves are compared with those of the evolution equation of the mild-slope equation [Hsu et al., 2002 Proceedings of the 24th Ocean Engineering Conference in Taiwan, pp. 70–77 (in Chinese)]. In addit