M Ebrahimian - Msc Student, Sharif University of Technology;
M. A. Noorian - Ph.D Candidate, Sharif University of Technology;
H. Haddadpour - Professor, Sharif University of Technology

The present work aims at developing an optimized boundary element method to fast determination of the natural frequencies and mode shapes of liquid sloshing in multi baffled tanks with arbitrary geometries. The Green’s theorem, the governing equations of fluid dynamic and free surface boundary condition, are used in this work to obtain an effective method to determine the sloshing frequencies. A zoning method is also developed to model arbitrary arrangements of baffles in multi baffled tanks. By this method, we can use governing equations on each zone separately from the others. By discretizing the flow boundaries, the boundary integral equation is formulated into a general matrix eigenvalue problem. In the proposed method, the minimum conceivable calculation is needed, so minimum CPU time with an acceptable accuracy is achieved. The results obtained using this model, are verified in comparison with the literature and very good agreement is achieved. Finally, a number of example tanks are used to investigate the effect of baffles on sloshing frequencies and some conclusions are outlined

liquid sloshing-boundary element methodnatural frequencies-multi baffled tank