Fuel sloshing is one of the most important factors in disturb attitude of the spacecraft from desire in orbital maneuver. So, controlling this phenomenon is a critical problem in attitude control. There are active and passive control methods to control fuel sloshing. Active method has better responses to control fuel sloshing and its effect on attitude of the spacecraft in the same time; so, mostly this method is used. For this aim, it is necessary to model slosh dynamic. In this paper, slosh dynamic is modeled by a multi-pendulum model, and, then, coupled equations of the spacecraft and fuel slosh dynamic are derived. In the presented model, pendulums can move freely in 3D atmosphere, and this matter makes presented model closer to real. Coupled equations of the spacecraft and fuel slosh dynamic are Nonlinear. Therefore, Nonlinear control methods should be used to attitude control in more realistic mode. In this paper, two candidate Lyapunov functions are proposed; then, using these functions, controllers are obtained. The effectiveness of these controllers on attitude of the spacecraft and pendulums is described by a simulation. Although, there are some little differences in time responses based on two controllers, results of simulation illustrate good responsibility of controllers to control aims.

The sloshing phenomena in a partially filled tank can affect its stability. Modifications of tank instability due to the movement of the tank carrier are key design points for the stability of a carrier. Even though the sloshing phenomenon has already been investigated using the BEM-FDM technique, the research in this paper covers this phenomenon in a porous media, which is new in 2-D coordinates. For this purpose, a Laplace equation has been used for potential flow, and kinematic and dynamic boundary conditions have been applied to the free surface. Also, a formulation has been developed for a free surface in porous media. BEM has been used for solving the governing equation and FDM discretization has been used for kinematic and dynamic free surface boundary conditions and for time marching. Theoretical results have been verified with experimental data collected in this study. The results show an acceptable agreement between theory and experiment, and the rapid damping property in the sloshing phenomena by using porous material in the water, as expected. Also, these results illustrate that the derived formula in this research are applicable and true.

The motion of fluids within partially filled containers has been the subject of much study by scientists and engineers due, in large part, to its importance in many practical applications. For example, civil engineers and seismologists have actively studied the effects of earthquake-induced fluid motions on oil tanks and water towers. In recent years, aerospace engineers have been concerned with the effect of fluid sloshing within propellant tanks on the stability of aircraft, rockets, and satellites. All of these applications seek container designs which minimize the amplitude of fluid forces over again range of operating conditions. In this paper, an incompressible smoothed particle hydrodynamics (SPH) method is developed to numerically simulate viscous free surface flows in partially filled containers. The mass conservation and Navier-Stokes equations are solved as basic equations. The method uses a prediction-correction fractional step technique. In the prediction step, the temporal velocity field is integrated in time without enforcing incompressibility and in the correction step the resulting deviation of particle density is implicitly projected onto a divergence-free space to satisfy incompressibility through a pressure Poisson equation derived fr an approximate pressure projection. The proposed SPH method is used to simulate the sloshing of a omliquid wave with low amplitude under the influence of gravity. Initial shape of free surface is defined by one half of a cosine wave with low amplitude. The results of simulation are in good agreement with experimental and other modeling data.

In this paper, the fluid characteristics of pitching sloshing under microgravity condition are investigated. A numerical method by solving the Navier-Stokes equations to study three-dimensional (3-D) Nonlinear liquid sloshing is developed with OpenFOAM, a Computational Fluid Dynamics (CFD) tool. The computational method is validated against existing experimental data in rectangular tank under ordinary gravitational field. However under low gravity conditions, the sloshing liquid shows seemingly chaotic behavior and a considerable volume of liquid attaches on the sidewall due to the effect of surface tension, which is verified in simulation experiment. Besides, the Nonlinear liquid behaviors in hemi-spherically bottom tank are firstly studied in this paper. It is found that the wave evolution becomes divergent with the decrease of gravitational acceleration. The natural frequency reaches a constant magnitude quickly with the increase of liquid height and then increases again until the filling level exceeds 70%. Meanwhile, the liquid dynamics of forced pitching sloshing under resonant and off-resonant condition are demonstrated respectively. The numerical techniques for 3-D simulation are hopeful to provide valuable guidance for efficient liquid management in space.

This study aimed to explore the seismic responses of the water-filled prestressed concrete cylindrical tanks. To this end, a number of dynamic-explicit studies are carried out in order to investigate the implications that the water sloshing phenomenon has on the behavior of the prestressed concrete tank when it is subjected to earthquake inputs. Using previous research demonstrates that our numerical analysis is capable of representing the sloshing waves. In addition, a shaking table test is carried out to verify the accuracy of the numerical analysis. The main highlight of the numerical simulation method is to consider all components and elaborate detailing of prestressed tanks. The novelty of this study is to model the 3D sloshing of the liquid in the prestressed concrete tanks. Comparing the experimental and numerical results demonstrates a reasonable agreement between them. Also, in this research, the dynamic-explicit method is applied accompanying the Arbitrary Lagrangian–Eulerian (ALE) adaptive meshing to enhance the numerical model for Nonlinear sloshing wave simulation. An experiment is performed on a prestressed concrete containment sample in the shaking table of the Amirkabir University of Technology to assess the efficiency of numerical analysis. The numerical results show the robustness of the water simulation method in which almost shows realistic motions of water mass points in the ALE method.

This study aims to consider the sloshing height and hydrodynamic pressure in roofless and roofed liquid storage tanks utilizing a coupled FE-SPH technique. As a design technique for determining the necessary analyses and main parameters to reach reasonable results, the Taguchi method is used. The SPH formulation models the liquid concerning the large amplitude sloshing waves, and the finite element method simulates the structure. At first, it is found that expressions presented in ACI 350.3-06 should be revised when calculating the sloshing height in a rectangular tank. Secondly, when determining the hydrodynamic pressure applied on the roof and, also the sloshing height, the frequency content of the input ground motion affects significantly the contained liquid responses. Comparison of the results obtained for roofed and roofless tanks indicate no clear correlation between their dynamic responses. The results of this study suggest the ratio of liquid height to its length, the length itself, and earthquake record PGA as noise parameters in Taguchi analysis. At last, the suggested Taguchi analysis’s main design parameters for future studies are the acceleration spectrum intensity ASI and the liquid’s height in the storage tank.