scholarly journals Study on liquid sloshing characteristics of a swaying rectangular tank with a rolling baffle

2019 ◽  
Vol 119 (1) ◽  
pp. 23-41 ◽  
Author(s):  
Jing-Han Wang ◽  
Shi-Li Sun
Keyword(s):  
Free Surface ◽  
Present Method ◽  
Velocity Potential ◽  
Solution Procedure ◽  
Liquid Sloshing ◽  
Published Data ◽  
Free Surface Elevation ◽  
Separate Variable ◽  
Rectangular Tank ◽  
Vertical Baffle

Abstract This study addresses the sloshing characteristics of a liquid contained in a tank with a vertical baffle mounted at the bottom of the tank. Liquid sloshing characteristics are studied through an analytical solution procedure based on the linear velocity potential theory. The tank is forced to sway horizontally and periodically, while the baffle is fixed to the tank or rolling around a hinged point. The rectangular tank flow field is divided into a few sub-domains. The potentials are solved by a separate variable method, and the boundary conditions and matching requirements between adjacent sub-domains are used to determine the sole solution. The free surface elevations with no baffle or a low fixed baffle are compared with those in published data, and the correctness and reliability of the present method are verified. Then the baffle is forced to rotate around the bottom-mounted point. It is found that the baffle’s motion, including the magnitude and the phase together, can be adjusted to suppress the free surface elevation, and even the sloshing wave can be almost eliminated.

scholarly journals Numerical Modeling of Coupled Surge-Heave Sloshing in a Rectangular Tank with Baffles

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Lv Ren ◽  
Yinjie Zou ◽  
Jinbo Tang ◽  
Xin Jin ◽  
Dengsong Li ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Free Surface ◽  
Numerical Model ◽  
Frequency Response ◽  
Navier Stokes ◽  
Rectangular Tank ◽  
Vertical Baffle ◽  
Tank Bottom ◽  
Violent Sloshing ◽  
Effective Water

Liquid sloshing under coupled surge and heave excitations in a rectangular tank has been numerically investigated by applying a Navier–Stokes solver. Fieriest coupled sloshing was further considered, and the internal baffle was expected to suppress the violent sloshing wave. After getting fully validated against available results from the literatures, the numerical model was applied to research coupled sloshing, and both vertical baffle and horizontal baffle have been considered. Due to the strong vortexes created by the sharper corners of the baffles and the reduction of the effective water bulk climbing through the tank walls, the sloshing was dramatically reduced. The increase of the baffle distance away from the tank bottom led to a decrease in the sloshing wave. It was noted that the baffle near the free surface caused the maximal dissipation. The frequency response of the sloshing wave was accordingly illustrated.

scholarly journals Asymmetric impact between liquid and solid wedges

2013 ◽  
Vol 469 (2150) ◽  
pp. 20120203 ◽  
Author(s):  
Y. A. Semenov ◽  
G. X. Wu
Keyword(s):  
Free Surface ◽  
Velocity Potential ◽  
Mapping Function ◽  
Solution Procedure ◽  
Contact Angles ◽  
The Body ◽  
Surface Shape ◽  
Parameter Plane ◽  
Complex Velocity Potential ◽  
The Impact

The hydrodynamic problem of impact between a solid wedge and a liquid wedge is analysed. The liquid is assumed to be ideal and incompressible; gravity and surface tension effects are ignored. The flow generated by the impact is assumed to be irrotational and therefore can be described by the velocity potential theory. The solution procedure is based on the analytical derivation of the complex-velocity potential in a parameter plane and the function mapping conformally the parameter plane onto the similarity plane. The mapping function is found as a combination of the derivatives of the complex potential in the similarity and parameter planes, through the integral equations for mixed and homogeneous boundary-value problems in terms of the velocity modulus and the velocity angle with the fluid boundary, together with the dynamic and kinematic boundary conditions. These equations are solved through a numerical method. The procedure is first verified through comparisons with some known results. Simulations are then made for a variety of cases, and detailed results are presented in terms of the free surface shape, streamlines, pressure distribution on the wetted solid surface, and contact angles between the free surface and the body surface.

Multidimensional modal analysis of nonlinear sloshing in a rectangular tank with finite water depth

2000 ◽  
Vol 407 ◽  
pp. 201-234 ◽  
Author(s):  
ODD M. FALTINSEN ◽  
OLAV F. ROGNEBAKKE ◽  
IVAN A. LUKOVSKY ◽  
ALEXANDER N. TIMOKHA
Keyword(s):  
Free Surface ◽  
Water Depth ◽  
Velocity Potential ◽  
Initial Conditions ◽  
Modal System ◽  
Infinite Dimensional ◽  
Nonlinear Sloshing ◽  
Generalized Fourier Series ◽  
Rectangular Tank ◽  
Finite Water Depth

The discrete infinite-dimensional modal system describing nonlinear sloshing of an incompressible fluid with irrotational flow partially occupying a tank performing an arbitrary three-dimensional motion is derived in general form. The tank has vertical walls near the free surface and overturning waves are excluded. The derivation is based on the Bateman–Luke variational principle. The free surface motion and velocity potential are expanded in generalized Fourier series. The derived infinite-dimensional modal system couples generalized time-dependent coordinates of free surface elevation and the velocity potential. The procedure is not restricted by any order of smallness. The general multidimensional structure of the equations is approximated to analyse sloshing in a rectangular tank with finite water depth. The amplitude–frequency response is consistent with the fifth-order steady-state solutions by Waterhouse (1994). The theory is validated by new experimental results. It is shown that transients and associated nonlinear beating are important. An initial variation of excitation periods is more important than initial conditions. The theory is invalid when either the water depth is small or water impacts heavily on the tank ceiling. Alternative expressions for hydrodynamic loads are presented. The procedure facilitates simulations of a coupled vehicle–fluid system.

Numerical Simulation of Nonlinear Sloshing in a 2D Vertically Moving Container

2013 ◽  
Vol 819 ◽  
pp. 409-413
Author(s):  
Hai Tao Zhang ◽  
Bei Bei Sun
Keyword(s):  
Numerical Simulation ◽  
Free Surface ◽  
Finite Difference ◽  
Finite Difference Method ◽  
Difference Method ◽  
Linear Equations ◽  
Liquid Sloshing ◽  
Free Surface Elevation ◽  
Time Layer ◽  
Rectangular Area

Nonlinear liquid sloshing problems in a vertically excited tank are numerically simulated by using a finite difference method. First, the irregular liquid domain is mapped onto a rectangular area by σ-transformation. Then, in the process of time iteration, the free surface is forecasted to estimate the boundary of the next time layer; and some nonlinear terms are approximated to derive linear equations. Free surface elevation and sloshing forces in the vertical sloshing process can be calculated precisely by this method.

Computational Modelling of Liquid Sloshing in Rectangular Tank

2013 ◽  
Vol 365-366 ◽  
pp. 186-189 ◽  
Author(s):  
Marija Gradinscak ◽  
Farial Jafar
Keyword(s):  
Free Surface ◽  
Finite Difference ◽  
Computational Modelling ◽  
Volume Of Fluid ◽  
Liquid Sloshing ◽  
Time Step ◽  
Rectangular Tank ◽  
Numerical Tool ◽  
Acceptor Method

Liquid sloshing inside a partially filled rectangular tank has been investigated. The fluid is assumed to be water and the tank is forced to move along x axis to simulate the actual tank excitation. The volume of fluid technique is used to track the free surface and the model solves Navier_Stokes equations by the use of the finite difference estimation. At each time step, a donar-acceptor method is used to transport the volume of fluid function and locations of the free surface. In this paper the location and transport of the free surface in the tank have been investigated using a CFD code (FLUENT) for 3D configuration. The use of a numerical tool has resulted in a detailed investigation of these characteristics, which have not been available in the literature previously.

scholarly journals Numerical Simulation of Sloshing Phenomena in Cubic Tank with Multiple Baffles

2012 ◽  
Vol 2012 ◽  
pp. 1-21 ◽  
Author(s):  
Mi-An Xue ◽  
Jinhai Zheng ◽  
Pengzhi Lin
Keyword(s):  
Stokes Equations ◽  
Numerical Data ◽  
Liquid Sloshing ◽  
Navier Stokes ◽  
Free Surface Elevation ◽  
Dynamic Impact ◽  
Two Phase ◽  
Navier Stokes Equations ◽  
Vertical Baffle ◽  
Phase Fluid

A two-phase fluid flow model solving Navier-Stokes equations was employed in this paper to investigate liquid sloshing phenomena in cubic tank with horizontal baffle, perforated vertical baffle, and their combinatorial configurations under the harmonic motion excitation. Laboratory experiment of liquid sloshing in cubic tank with perforated vertical baffle was carried out to validate the present numerical model. Fairly good agreements were obtained from the comparisons between the present numerical results and the present experimental data, available numerical data. Liquid sloshing in cubic tank with multiple baffles was investigated numerically in detail under different external excitation frequencies. Power spectrum of the time series of free surface elevation was presented with the aid of fast Fourier transform technique. The dynamic impact pressures acting on the normal and parallel sidewalls were discussed in detail.

Experimental and Numerical Study on Liquid Sloshing Dynamics with Single Vertical Porous Baffle in a Sway Excited Ship Tank

2020 ◽  
Author(s):  
Sahaj k v ◽  
Nasar Thuvanismail
Keyword(s):  
Free Surface ◽  
Boundary Element ◽  
Numerical Study ◽  
Excitation Frequency ◽  
Boundary Element Methods ◽  
Liquid Sloshing ◽  
Shake Table ◽  
Natural Period ◽  
Rectangular Tank ◽  
Porous Screen

<p>Liquid motion in partially filled tanks may cause large structural loads if the period of tank motion is close to the natural period of fluid inside the tank. This phenomenon is called sloshing. Sloshing means any motion of a free liquid surface inside a container. The effect of severe sloshing motion on global seagoing vessels is an important factor in safety design of such containers. In order to examine the sloshing effects, a shake table experiments were conducted for different water fill depth of aspect ratio 0.163, 0.325 and 0.488. The parametric studies were carried out to show the liquid sloshing effects in terms of slosh frequencies, maximum free surface elevation and hydrodynamic forces acting on the tank wall. Sloshing oscillation for the excitation frequency f<sub>1</sub>, f<sub>2</sub>, f<sub>3</sub>, f<sub>4 </sub>and f<sub>5</sub> are observed and analysed. The excitation frequencies is varied between 0.4566 Hz to 1.9757 Hz and constant amplitudes of 7.5mm was adopted. The movement of fluid in a rectangular tank has been studied using experimental approach and different baffle configurations were adopted for analysing the sloshing oscillation, natural frequencies and variation in wave deflection. The adopted porosities in the present study is 15% – 25 %. Porous screen is placed inside the tank at L/2 location and study is extended for single porous screen for better wave energy absorption. Capacitance wave probes have been placed at tank ends to record the free surface water elevation. Load cells are used to measure the sloshing force inside the tank. Linear variable displacement transducers is used to measure the displacement of shake table. In the present study single porous screen under the action of wave were analysed to understand the wave control performance due to porosity parameters. A boundary element model is developed to calculate problems of wave interaction with a porous screen structure. The numerical results from the present boundary element methods (BEM) are compared with series of experiments conducted in a rectangular tank with various baffle porosities and submerged depths.</p><p> </p>

Numerical Investigation of Focused Waves and Their Interaction With a Vertical Cylinder Using REEF3D

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Hans Bihs ◽  
Mayilvahanan Alagan Chella ◽  
Arun Kamath ◽  
Øivind Asgeir Arntsen
Keyword(s):  
Free Surface ◽  
Stokes Equations ◽  
Free Surface Flows ◽  
Surface Elevation ◽  
Numerical Wave Tank ◽  
Free Surface Elevation ◽  
Wave Tank ◽  
Numerical Wave ◽  
Focused Wave ◽  
The Impact

For the stability of offshore structures, such as offshore wind foundations, extreme wave conditions need to be taken into account. Waves from extreme events are critical from the design perspective. In a numerical wave tank, extreme waves can be modeled using focused waves. Here, linear waves are generated from a wave spectrum. The wave crests of the generated waves coincide at a preselected location and time. Focused wave generation is implemented in the numerical wave tank module of REEF3D, which has been extensively and successfully tested for various wave hydrodynamics and wave–structure interaction problems in particular and for free surface flows in general. The open-source computational fluid dynamics (CFD) code REEF3D solves the three-dimensional Navier–Stokes equations on a staggered Cartesian grid. Higher order numerical schemes are used for time and spatial discretization. For the interface capturing, the level set method is selected. In order to test the generated waves, the time series of the free surface elevation are compared with experimental benchmark cases. The numerically simulated free surface elevation shows good agreement with experimental data. In further computations, the impact of the focused waves on a vertical circular cylinder is investigated. A breaking focused wave is simulated and the associated kinematics is investigated. Free surface flow features during the interaction of nonbreaking focused waves with a cylinder and during the breaking process of a focused wave are also investigated along with the numerically captured free surface.

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