Parametric study for optimization of storage tanks considering sloshing phenomenon using coupled BEM–FEM

• Maximum pressure on the rectangular tank perimeter is minimized for aspect ratios in a range of 0.3–0.4.
• Maximum pressure on linear sidewall trapezoidal tank perimeter decreases about 60% for θ = 65° and 115° respect to rectangular one.
• As the trapezoidal tank width decreases the maximum pressure occurs in sidewalls angles close to θ = 90°.
• Maximum pressure on quadratic sidewall trapezoidal tank perimeter decreases about 67% respect to rectangular one.

Evaluation of the fluid dynamic loads due to liquid sloshing in partially filled compartments is essential for designing a ship carrying liquids. Different geometric shapes such as rectangular, cylindrical, elliptical, spherical and circular conical have already been suggested for ship storage tanks by other researchers. In this paper, a new arrangement, i.e. trapezoidal containers was suggested for liquid storage tanks. The tank shape was optimized based on sloshing pressures and forces for a range of frequencies and amplitudes of sway motion and tank configuration. Considering the fluid to be incompressible and inviscid, Laplace equation and nonlinear free surface boundary conditions were used to model the sloshing phenomenon. A numerical model was developed based on coupled BEM–FEM to solve these equations. The model results were validated using available data from Nakayama and Washizu. The results showed that the suggested geometric shapes, not only have a maximum surrounded tank volume to the constant available volume, but also reduce the sloshing effects more efficiently than the available geometric shapes.