NUMERICAL STUDY ON BEHAVIOR OF THE TRAPEZOIDAL STORAGE TANK DUE TO LIQUID SLOSHING IMPACT

2013 ◽  
Vol 10 (06) ◽  
pp. 1350046 ◽  
Author(s):  
M. J. KETABDARI ◽  
H. SAGHI
Keyword(s):  
Numerical Study ◽  
Liquid Sloshing ◽  
Surface Boundary ◽  
Storage Tanks ◽  
Liquid Storage ◽  
Surface Boundary Conditions ◽  
Sloshing Phenomenon ◽  
Nonlinear Free Surface ◽  
Sway Motion ◽  
Sloshing Pressure

In this paper, a numerical model is developed based on coupled boundary element–finite element methods (BEM–FEM) to minimize liquid sloshing pressure in trapezoidal tank with different sidewall angles. Different geometric shapes such as rectangular, cylindrical, elliptical, spherical and circular conical have already been studied for ship storage tanks by other researchers. In this paper, a new arrangement, i.e., trapezoidal containers is suggested for liquid storage tanks. The tank shape is optimized based on sloshing pressures and forces for a range of frequencies and amplitudes of sway motion and tank configuration. Fluid is considered to be incompressible and inviscid. Therefore, Laplace equation and nonlinear free surface boundary conditions are used to model the sloshing phenomenon. The results validated using available data showed that a new arrangement of trapezoidal storage panels has a better efficiency against sloshing phenomenon than the conventional rectangular tanks.

A numerical nonlinear analysis of two-dimensional ventilating entry of surface-piercing hydrofoils with effects of gravity

2010 ◽  
Vol 658 ◽  
pp. 383-408 ◽  
Author(s):  
VIMAL VINAYAN ◽  
SPYROS A. KINNAS
Keyword(s):  
Free Surface ◽  
Boundary Conditions ◽  
Numerical Scheme ◽  
Suction Side ◽  
Nonlinear Boundary Conditions ◽  
Surface Boundary ◽  
Two Dimensional ◽  
Surface Boundary Conditions ◽  
Dimensional Boundary ◽  
Nonlinear Free Surface

The presence of the free surface adds an element of difficulty to the development of numerical and theoretical methods for the performance prediction of surface-piercing hydrofoils. Existing methods of analysis for two-dimensional surface-piercing hydrofoils or blade sections of a surface-piercing propeller solve either a linear problem, assuming a thin section and ventilated surface along with linear free-surface boundary conditions, or a nonlinear problem in a self-similar setting. Both these approaches cannot be used when the effects of gravity are important, which is the case when a craft is operating at low speeds. A two-dimensional boundary-element-method-based numerical scheme is presented here that overcomes these drawbacks by solving the fully ventilated flow past a surface-piercing hydrofoil of finite dimensions and includes the whole gamut of nonlinear free-surface interactions. The unique aspect of the numerical scheme is that fully nonlinear boundary conditions are applied on the free surface which allows for the accurate modelling of the jet generated on the wetted boundary and the ventilated surface formed on the suction side as a result of the passage of the hydrofoil through the free surface. Moreover, the effects of gravity can be considered to take into account the influence of the Froude number. Ventilated-surface shapes predicted by the present scheme are compared with existing experimental results and are shown to be in good agreement.

scholarly journals Numerical Investigation of Wave-Body Interactions in Shallow Water

2014 ◽  
Author(s):  
Yi Luo ◽  
Torgeir Vada ◽  
Marilena Greco
Keyword(s):  
Free Surface ◽  
Boundary Conditions ◽  
Numerical Study ◽  
Surface Boundary ◽  
Regular Waves ◽  
Incoming Wave ◽  
Surface Boundary Conditions ◽  
First Case ◽  
Non Linear ◽  
Linear Effects

Present investigation is based on a numerical study using a time-domain Rankine panel method. The effort and novelty is to extend the applicability of the solver to shallower waters and to steeper waves by including additional non-linear effects, but in a way so to limit the increase in computational costs. The challenge is to assess the improvement with respect to the basic formulation and the recovery of linear theory in the limit of small waves. The wave theories included in the program are Airy, Stokes 5th order and Stream function. By their comparison the effect of the incoming-wave non-linearities can be investigated. For the free-surface boundary conditions two alternative formulations are investigated, one by Hui Sun [1] and one developed here. The two formulations combined with the above-mentioned wave theories are applied to two relevant problems. The first case is a fixed vertical cylinder in regular waves, where numerical results are compared with the model tests by Grue & Huseby [2]. The second case is a freely floating model of a LNG carrier (with zero forward speed) in regular waves, where computations are compared with the experimental results from the EC project “Extreme Seas”. This comparison revealed several challenges such as how to interpret/post process the experimental data. Some of these are described in the paper. After careful handling of both computed and measured data the comparisons show reasonable agreement. It is proven that including more non-linear effects in the free-surface boundary conditions can significantly improve the results. The formulation by Hui Sun gives better results compared to the linear condition, but the present formulation is shown to provide a further improvement, which can be explained through the nonlinear terms included/retained in the two approaches.

Damage observations and remedial options for approximately 1500 legged and flat-based liquid storage tanks following the 2016 Kaikōura earthquake

Structures ◽  
2020 ◽  
Vol 24 ◽  
pp. 357-376 ◽  
Author(s):  
Mohsen Yazdanian ◽  
Jason M. Ingham ◽  
Will Lomax ◽  
Regan Wood ◽  
Dmytro Dizhur
Keyword(s):  
Storage Tanks ◽  
Liquid Storage ◽  
Kaikoura Earthquake
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