Simulation dammbruchinduzierter Flutwellen

This thesis deals with the development of a two-dimensional explicit FE model for solving the non-conservative formulation of the shallow water equations. The algorithm is a combination of the 'through-method' and the 'shock-fitting-method', while significantly maintaining the high efficiency of the 'through-method'. Starting from Stoker's solution, numerical investigations lead to simple shock-fitting using a momentum correction which requires low computation time. The solution domain is not divided into subdomains, as is characteristic of the classical 'shock-fitting method'. Two special algorithms were developed to reduce oscillations, with a view towards minimizing damping effects. The first uses a mixed interpolation function which corresponds to the stability condition of Brezzi-Babuska. The other consists of a Streamline-Upwind-Petrov-Galerin-method (SUPG-method) which does not fulfill the Brezzi-Babuska stability condition, but allows the deliberate use of numerical diffusion. Verification of the model was achieved using the well-known analytical solutions of Ritter and Stoker, and by comparison with hydraulic model data. The solutions obtained from both implemented algorithms were also compared with each other. Both were found to be robust and highly accurate. Some damping was found in the SUPG method, since the exact choice of the appropriate upwind parameters is very difficult. (orig.)Available from TIB Hannover: RO 2460(46)+a+b / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman