The coupling oscillation of a liquid in a cylindrical tank with an elastic slosh baffle is investigated. Free surface conditions are considered in the study. The complexity of the coupled boundary-value problem for th...The coupling oscillation of a liquid in a cylindrical tank with an elastic slosh baffle is investigated. Free surface conditions are considered in the study. The complexity of the coupled boundary-value problem for the liquid and elastic damping spacer results in significant analytical difficulties. Two different velocity potential functions are respectively used in the liquid domain above, or below the damping spacer. A coupled frequency equation is obtained by using the pair of velocity potential functions. The numerical and theoretical analysis show that the natural frequency changes according to the location and stiffness of the spacer. Results indicate that the frequency coupling between damping spacer and sloshing liquid is obvious near the free liquid surface. It is shown that the coupling frequency increases with the increase of damping baffle rigidity.展开更多
With the development of large liquid cargo ships,liquid tank sloshing has gradually become a hot research topic in the area of shipping and ocean Engineering.Liquid tank sloshing,characterized by strong nonlinearity a...With the development of large liquid cargo ships,liquid tank sloshing has gradually become a hot research topic in the area of shipping and ocean Engineering.Liquid tank sloshing,characterized by strong nonlinearity and randomness,not only affects the stability of the ship but also generates a huge impact force on the wall of the tank.To further investigate liquid tank sloshing,a comprehensive review is given on the research process of the most focused subjects of liquid sloshing.Summarizing the existing research will help to identify issues in the current field and provide useful references.The methods for investigating sloshing,the research progress and the situations worldwide are discussed.The advantages and defects of experiments and numerical simulations are also explored.The problems which need to be explored in the future are subsequently proposed.展开更多
The influence of baffle position on liquid sloshing during the braking and turning of a tank truck was studied using a volume of fluid (VOF) model. The forces,their positions and weight distribution during braking and...The influence of baffle position on liquid sloshing during the braking and turning of a tank truck was studied using a volume of fluid (VOF) model. The forces,their positions and weight distribution during braking and the forces and rolling moment during turning were calculated. The reliability of the calculation method was validated by comparisons with experimental results. The results showed that during braking,liquid splashes in the tank and the maximum forces and G (the ratio of weight acting on the front axle to the rear axle) are large when A (the ratio of the arch area above the baffle to the area of cross section)≤0.1. When A≥0.2,as the position of the baffle is lowered,the maximum of Fx (the force in direction x) first decreases then increases,and the maximum of Fy (the force in direction y) and G increase. During turning,liquid splashes in the tank and the maximum forces and M (the rolling moment) are large when D (the ratio of the arch area above the baffle to the area of cross section)≤0.2. When D≥0.3,as the position of the baffle is lowered,the maximums of Fy,Fz (the force in direction z) and M increase.展开更多
A sloshing experiment is conducted to study the hydroelastic effect in an elastic tank. For this purpose, a translational harmonic excitation is applied to a 2-D rectangular tank model. The lowest-order natural freque...A sloshing experiment is conducted to study the hydroelastic effect in an elastic tank. For this purpose, a translational harmonic excitation is applied to a 2-D rectangular tank model. The lowest-order natural frequencies of the liquid in the tank are determined through the sweep test. The wave elevation and the sloshing pressure are obtained by changing the excitation frequency and the liquid depth. Then the characteristics and the variation of the elevation and the pressure are discussed. The results are compared with the experimental results and the theoretical calculations in a rigid tank. Our analysis indicates that, in the non- resonant cases, the elastic results, the rigid experimental results and the theoretical values are all close to each other. In contrast, under the resonant condition, the elastic experimental result is slightly smaller than the rigid one. Also, the theoretical values are smaller than the experimental results at the resonant frequency.展开更多
In this paper,a multiphase moving particle semi-implicit(MPS)method is developed by introduction of various multiphase models into the original MPS method for single-phase flows,and is then applied to the numerical si...In this paper,a multiphase moving particle semi-implicit(MPS)method is developed by introduction of various multiphase models into the original MPS method for single-phase flows,and is then applied to the numerical simulations of two-layer-liquid and three-layer-liquid sloshing in a 2-D rectangular tank under different external excitations.To validate the accuracy of the present multiphase MPS method,the qualitative and quantitative results,including wave profiles,interface elevations and impact pressures,are compared with experimental data and other numerical results,which show a good agreement.In particular,the evolutions of free surface and phase interfaces are compared and an obvious discrepancy is found,indicating that the phase interfaces may suffer from complex deformations while the free surface keeps relatively quiet.Moreover,the different modes of phase interface are observed under different excitation frequencies.Then,the violent sloshing of a three-layer-liquid system is simulated and the phenomenon of internal wave breaking is well captured,which mainly benefitted from the Lagrangian basis of MPS method and its advantage in multiphase flows with complex interfaces.Finally,the three-layer-liquid sloshing with a vertical baffle are simulated to investigate the suppressing effect of baffle on multi-layer-liquid sloshing.展开更多
The dynamics of liquid sloshing in a spherical tank with spacer under low gravity was investigated. By extending the characteristic functions, the frequencies of liquid free sloshing, reaction force and moments on th...The dynamics of liquid sloshing in a spherical tank with spacer under low gravity was investigated. By extending the characteristic functions, the frequencies of liquid free sloshing, reaction force and moments on the wall of tank were obtained. By mechanical equivalent principle, the equivalent models of spring vibrator damper of liquid sloshing were given. The numerical results obtained show when a spacer is inserted in the tank, the sloshing frequency of liquid and the sloshing mass of liquid will decrease.展开更多
In this paper, the dynamics of liquid sloshing in a rectangular tank under low gravity was investigated. The basic frequencies and the velocity potentials of sloshing of liquid were obtained by expansion of the Fourie...In this paper, the dynamics of liquid sloshing in a rectangular tank under low gravity was investigated. The basic frequencies and the velocity potentials of sloshing of liquid were obtained by expansion of the Fourier series. The characteristics of force and moment of the liquid acting on a rectangular tank were analyzed. The equivalent mechanical models of spring-vibrator-damper of sloshing of liquid were established with mechanical equivalent principle and numerical results were given. The numerical results show that the equivalent sloshing mass increases with the increase of gravity, and that the basic frequency and the equivalent sloshing mass increase with the increase of the liquid depth.展开更多
Nonlinear coupling dynamics between a spring-mass system and a finite amplitude sloshing system with liquid in a cylindrical tank is investigated. Based on a group of nonlinear coupling equations of six degrees of fre...Nonlinear coupling dynamics between a spring-mass system and a finite amplitude sloshing system with liquid in a cylindrical tank is investigated. Based on a group of nonlinear coupling equations of six degrees of freedoms, analytical formulae of forces and moments of the liquid large amplitude sloshing were obtained. Nonlinearity of the forces and moments of the sloshing was induced by integrating on final configuration of liquid sloshing and the nonlinear terms in the liquid pressure formula. The symmetry between the formula of Ox and Oy direction proves that the derivation is correct. According to the coupled mechanism, the formulae are available in other liquid-solid coupled systems. Simulations and corresponding experimental results arecompared. It is shown that the forces and moments formulae by integrating on the final sloshing configuration are more reasonable. The omitted high-dimensional modal bases and high-order nonlinear terms and the complexity of sloshing damping are main sources of errors.展开更多
The density and viscosity ratios on partially liquid-filled sloshing with baffle have been investigated numerically in this study.As the key to success in the present simulation,the Coupled Level Set and the Volume of...The density and viscosity ratios on partially liquid-filled sloshing with baffle have been investigated numerically in this study.As the key to success in the present simulation,the Coupled Level Set and the Volume of Fluid(CLSVOF)method and the Immersed Boundary(IB)method are used to capture gas/liquid and fluid/structure interfaces,respectively.Within the CLSVOF method,surface normal in weighting factors is calculated by the level set function,resulting in a more accurate solution.Furthermore,the Tangent of Hyperbola for INterface Capturing(THINC)coupled with the Weighted Linear Interface Calculation(WLIC)scheme is used for capturing moving interface.As a standard practice,we first validate the code by comparing it with experimental results of liquid sloshing,which involves large deformation of interface.In addition to the validation study of the present method,the problems of liquid sloshing with baffle are investigated to understand kinematics and dynamics behaviors under different density and viscosity ratios.展开更多
Liquid sloshing is a kind of very complicated free surface flow and exists widely in many fields.In order to calculate liquid sloshing damping precisely a volume of fluid method based on finite volume scheme is used t...Liquid sloshing is a kind of very complicated free surface flow and exists widely in many fields.In order to calculate liquid sloshing damping precisely a volume of fluid method based on finite volume scheme is used to simulate free surface flows in partly filled cylindrical containers.A numerical method is pre-sented to simulate the movement of the free surface flow,in which a piecewise linear interface con-struction scheme and an unsplit Lagrangian advection scheme instead of Eulerian advection scheme are used.The damping performance of liquid sloshing in cylindrical containers under fundamental sloshing mode is investigated.There are four factors determining the surface-wave damping:free surface,boundary-layer,interior fluid and contact line.In order to study different contributions from these four factors to whole damping,several examples are simulated.No-slip and slip wall boundary conditions on both side wall and bottom wall of the cylindrical containers are studied to compare with the published results obtained by solving Stokes equations.In the present method the first three main factors can be considered.The simulation results show that the boundary-layer damping contribution increases while the interior fluid damping contribution decreases with increase of Reynolds number.展开更多
Large-scale amplitude liquid sloshing in container under pitching excitation is numerically studied in this paper.Firstly,the kinematics of the ALE description is introduced and the fluid dynamics equations are revise...Large-scale amplitude liquid sloshing in container under pitching excitation is numerically studied in this paper.Firstly,the kinematics of the ALE description is introduced and the fluid dynamics equations are revised in the ALE form.Secondly,the boundary condition about free-surface tension is represented in the form of weak integration that can be computed by the differential geometry method derived in the present paper and the normal vector on free surface is calculated using accurate formulas presented in this paper.Then the numerical discretized equations of fractional step finite element method are developed by Galerkin weighted residual method.Furthermore,the numerical simulation of large-scale amplitude sloshing of the liquid both in rectangular container and cylindrical container is carried out.The computed time evolution of the wave height,and free surface profiles at different time are obtained.Comparisons among the present numerical results with other published numerical results and experimental data confirm the effectiveness and validity of the method developed in this paper.展开更多
The dynamic characteristics of liquid sloshing in a transversely vibrating spherical tank with spacer under low gravity were investigated. By expanding the characteristic functions, the frequencies and velocity potent...The dynamic characteristics of liquid sloshing in a transversely vibrating spherical tank with spacer under low gravity were investigated. By expanding the characteristic functions, the frequencies and velocity potentials of liquid free-sloshing were obtained. The dynamic equations and boundary conditions of liquid sloshing in the traverse vibrational spherical tank with spacer under low gravity were derived. By modifying the velocity potentials of liquid free-sloshing, the velocity potentials of liquid sloshing in the traverse vibrating spherical tank with a spacer were obtained. Furthermore, the forces and the moments acting on tank wall were given. The numerical results show when a spacer is inserted in the tank, the sloshing frequencies of liquid and the forces acting on tank wall will decrease, but the moment of force to the centre of the tank which is caused by the force of liquid acting on the spacer will occur.展开更多
In this paper, the couple vibration of liquid and elastic spacer in arectangular tank is investigated. Two different velocity potential functions correspondingrespectively to the liquid above and below the elastic spa...In this paper, the couple vibration of liquid and elastic spacer in arectangular tank is investigated. Two different velocity potential functions correspondingrespectively to the liquid above and below the elastic spacer are assumed. Complicated boundaryconditions corresponding to two velocity potential functions and vibrations of elastic spacer aregiven. Using the method of energy, the equation of couple frequency is obtained. Through numericalcomputation the natural frequencies that change according to the location and stiffness of thespacer are shown.展开更多
The angle compensation method is adopted to detect sloshing waves by laser diffraction, in the case that the wavelength of the sloshing waves is much greater than that of the incident light. The clear diffraction patt...The angle compensation method is adopted to detect sloshing waves by laser diffraction, in the case that the wavelength of the sloshing waves is much greater than that of the incident light. The clear diffraction pattern is observed to be of asymmetry, involving orders, position and interval of the diffraction spots that are discovered during the light grazing incidence. It is found that the larger the angle of incidence is, the more obvious the asymmetry is. The higher the negative diffraction orders are, the smaller the intervals between spots are. On the contrary~ in the positive region, the higher the diffraction orders are, the larger the spot intervals are. The positive interval is larger than that of the same negative diffraction order. If the incident angle reaches 1.558 rad in the experiment, all positive diffraction orders completely vanish. Based on the mechanism of phase modulation and with the Fourier transform method, the relations between the incident angle and position, interval spaces, and orders of diffraction spots are derived theoretically. The theoretical calculations are compared with the experimental data, and the comparison shows that the theoretical calculations are in good agreement with the experimental measurement.展开更多
The mathematical formulation of sloshing dynamics for a partially liquid filleddewar container driven by the gravity jitter acceleration associated with slew motion isstudied.Explicit mathematical expressions to man...The mathematical formulation of sloshing dynamics for a partially liquid filleddewar container driven by the gravity jitter acceleration associated with slew motion isstudied.Explicit mathematical expressions to manage jitter accelerption associated withslew motion which is acting on the fluid systems in microgravity are derived. Thenumerical computation of sloshing dymamics is based on the non-inertia framecontainer bound coordinate and the solution of time-dependent three-dimensionalformulations of partial differential equations subject to initial and boundary conditions.The numerical computation of fluid viscous stress forces and moment fluctuationsexerted on the dewar container driven by jitter acceleration associated with slew motion is investigated.展开更多
The dynamical behavior of fluids affected by the asymmetric gravity jitter oscillations, in particular, the effect of surface tension on partially-filled rotating fluids in a Dewar tank imposed by time-dependent direc...The dynamical behavior of fluids affected by the asymmetric gravity jitter oscillations, in particular, the effect of surface tension on partially-filled rotating fluids in a Dewar tank imposed by time-dependent directions of background reduced gravity accelerations is investigated. Results show that the greater the components of background reduced gravity in radial and circumferential directions, the greater will be the tendency toward increasing amplitude and degrees of asymmetry of the liquid-vapor interface profiles.展开更多
The nonlinear equations of an elastic tank-liquid coupling system subjected to the external excitation are established.By means of the multi-scale method and the singularity theory,the bifurcation behaviors of the sys...The nonlinear equations of an elastic tank-liquid coupling system subjected to the external excitation are established.By means of the multi-scale method and the singularity theory,the bifurcation behaviors of the system are investigated and analyzed.The various nonlinear dynamical behaviors of the coupling system are obtained,which can further explain the relationship between the physical parameters and the bifurcation solutions.The results provide a theoretical basis to the realization of the parameter optimal control.展开更多
文摘The coupling oscillation of a liquid in a cylindrical tank with an elastic slosh baffle is investigated. Free surface conditions are considered in the study. The complexity of the coupled boundary-value problem for the liquid and elastic damping spacer results in significant analytical difficulties. Two different velocity potential functions are respectively used in the liquid domain above, or below the damping spacer. A coupled frequency equation is obtained by using the pair of velocity potential functions. The numerical and theoretical analysis show that the natural frequency changes according to the location and stiffness of the spacer. Results indicate that the frequency coupling between damping spacer and sloshing liquid is obvious near the free liquid surface. It is shown that the coupling frequency increases with the increase of damping baffle rigidity.
基金financially supported by the National Natural Science Foundation of China(Grant No.52271271)the National Key Research and Development Program of China(Grant No.2022YFE0104500)+1 种基金“Pioneer”and“Leading Goose”R&D Program of Zhejiang Province(Grant No.2022C03023)Zhejiang Provincial Natural Science Foundation of China(Grant No.LQ17E090003)。
文摘With the development of large liquid cargo ships,liquid tank sloshing has gradually become a hot research topic in the area of shipping and ocean Engineering.Liquid tank sloshing,characterized by strong nonlinearity and randomness,not only affects the stability of the ship but also generates a huge impact force on the wall of the tank.To further investigate liquid tank sloshing,a comprehensive review is given on the research process of the most focused subjects of liquid sloshing.Summarizing the existing research will help to identify issues in the current field and provide useful references.The methods for investigating sloshing,the research progress and the situations worldwide are discussed.The advantages and defects of experiments and numerical simulations are also explored.The problems which need to be explored in the future are subsequently proposed.
文摘The influence of baffle position on liquid sloshing during the braking and turning of a tank truck was studied using a volume of fluid (VOF) model. The forces,their positions and weight distribution during braking and the forces and rolling moment during turning were calculated. The reliability of the calculation method was validated by comparisons with experimental results. The results showed that during braking,liquid splashes in the tank and the maximum forces and G (the ratio of weight acting on the front axle to the rear axle) are large when A (the ratio of the arch area above the baffle to the area of cross section)≤0.1. When A≥0.2,as the position of the baffle is lowered,the maximum of Fx (the force in direction x) first decreases then increases,and the maximum of Fy (the force in direction y) and G increase. During turning,liquid splashes in the tank and the maximum forces and M (the rolling moment) are large when D (the ratio of the arch area above the baffle to the area of cross section)≤0.2. When D≥0.3,as the position of the baffle is lowered,the maximums of Fy,Fz (the force in direction z) and M increase.
基金supported by the National Natural Science Foundation of China(Grant No.51179030,51309038)
文摘A sloshing experiment is conducted to study the hydroelastic effect in an elastic tank. For this purpose, a translational harmonic excitation is applied to a 2-D rectangular tank model. The lowest-order natural frequencies of the liquid in the tank are determined through the sweep test. The wave elevation and the sloshing pressure are obtained by changing the excitation frequency and the liquid depth. Then the characteristics and the variation of the elevation and the pressure are discussed. The results are compared with the experimental results and the theoretical calculations in a rigid tank. Our analysis indicates that, in the non- resonant cases, the elastic results, the rigid experimental results and the theoretical values are all close to each other. In contrast, under the resonant condition, the elastic experimental result is slightly smaller than the rigid one. Also, the theoretical values are smaller than the experimental results at the resonant frequency.
基金supported by the National Natural Science Foundation of China(Grant Nos.52131102,51879159)the National Key Research and Development Program of China(Grant Nos.2019YFC0312400,2019YFB1704200).
文摘In this paper,a multiphase moving particle semi-implicit(MPS)method is developed by introduction of various multiphase models into the original MPS method for single-phase flows,and is then applied to the numerical simulations of two-layer-liquid and three-layer-liquid sloshing in a 2-D rectangular tank under different external excitations.To validate the accuracy of the present multiphase MPS method,the qualitative and quantitative results,including wave profiles,interface elevations and impact pressures,are compared with experimental data and other numerical results,which show a good agreement.In particular,the evolutions of free surface and phase interfaces are compared and an obvious discrepancy is found,indicating that the phase interfaces may suffer from complex deformations while the free surface keeps relatively quiet.Moreover,the different modes of phase interface are observed under different excitation frequencies.Then,the violent sloshing of a three-layer-liquid system is simulated and the phenomenon of internal wave breaking is well captured,which mainly benefitted from the Lagrangian basis of MPS method and its advantage in multiphase flows with complex interfaces.Finally,the three-layer-liquid sloshing with a vertical baffle are simulated to investigate the suppressing effect of baffle on multi-layer-liquid sloshing.
基金Project support by the Scientific Research Foundation of Anhui (Grant No:00021090) and the Science Foundation of Jiangsu Higher Education (Grant No:02KJD13004).
文摘The dynamics of liquid sloshing in a spherical tank with spacer under low gravity was investigated. By extending the characteristic functions, the frequencies of liquid free sloshing, reaction force and moments on the wall of tank were obtained. By mechanical equivalent principle, the equivalent models of spring vibrator damper of liquid sloshing were given. The numerical results obtained show when a spacer is inserted in the tank, the sloshing frequency of liquid and the sloshing mass of liquid will decrease.
基金Project supported by the Scientific Research Foundation of Anhui (Grant No:00021090) and the Natural Science Foundation of Jiansu Higher Education (Grant No:02KJD13004).
文摘In this paper, the dynamics of liquid sloshing in a rectangular tank under low gravity was investigated. The basic frequencies and the velocity potentials of sloshing of liquid were obtained by expansion of the Fourier series. The characteristics of force and moment of the liquid acting on a rectangular tank were analyzed. The equivalent mechanical models of spring-vibrator-damper of sloshing of liquid were established with mechanical equivalent principle and numerical results were given. The numerical results show that the equivalent sloshing mass increases with the increase of gravity, and that the basic frequency and the equivalent sloshing mass increase with the increase of the liquid depth.
文摘Nonlinear coupling dynamics between a spring-mass system and a finite amplitude sloshing system with liquid in a cylindrical tank is investigated. Based on a group of nonlinear coupling equations of six degrees of freedoms, analytical formulae of forces and moments of the liquid large amplitude sloshing were obtained. Nonlinearity of the forces and moments of the sloshing was induced by integrating on final configuration of liquid sloshing and the nonlinear terms in the liquid pressure formula. The symmetry between the formula of Ox and Oy direction proves that the derivation is correct. According to the coupled mechanism, the formulae are available in other liquid-solid coupled systems. Simulations and corresponding experimental results arecompared. It is shown that the forces and moments formulae by integrating on the final sloshing configuration are more reasonable. The omitted high-dimensional modal bases and high-order nonlinear terms and the complexity of sloshing damping are main sources of errors.
基金supported by the Natural Science Foundation of Zhejiang Province,China(Grant Nos.LY20D010009 and LHY22E080004)the Open Fund of Key Laboratory of Flood&Drought Disaster Defense,the Ministry of Water Resources,China(Grant No.KYFB202112071050).
文摘The density and viscosity ratios on partially liquid-filled sloshing with baffle have been investigated numerically in this study.As the key to success in the present simulation,the Coupled Level Set and the Volume of Fluid(CLSVOF)method and the Immersed Boundary(IB)method are used to capture gas/liquid and fluid/structure interfaces,respectively.Within the CLSVOF method,surface normal in weighting factors is calculated by the level set function,resulting in a more accurate solution.Furthermore,the Tangent of Hyperbola for INterface Capturing(THINC)coupled with the Weighted Linear Interface Calculation(WLIC)scheme is used for capturing moving interface.As a standard practice,we first validate the code by comparing it with experimental results of liquid sloshing,which involves large deformation of interface.In addition to the validation study of the present method,the problems of liquid sloshing with baffle are investigated to understand kinematics and dynamics behaviors under different density and viscosity ratios.
基金Supported by the National Natural Science Foundation of China(Grant No.10532010)
文摘Liquid sloshing is a kind of very complicated free surface flow and exists widely in many fields.In order to calculate liquid sloshing damping precisely a volume of fluid method based on finite volume scheme is used to simulate free surface flows in partly filled cylindrical containers.A numerical method is pre-sented to simulate the movement of the free surface flow,in which a piecewise linear interface con-struction scheme and an unsplit Lagrangian advection scheme instead of Eulerian advection scheme are used.The damping performance of liquid sloshing in cylindrical containers under fundamental sloshing mode is investigated.There are four factors determining the surface-wave damping:free surface,boundary-layer,interior fluid and contact line.In order to study different contributions from these four factors to whole damping,several examples are simulated.No-slip and slip wall boundary conditions on both side wall and bottom wall of the cylindrical containers are studied to compare with the published results obtained by solving Stokes equations.In the present method the first three main factors can be considered.The simulation results show that the boundary-layer damping contribution increases while the interior fluid damping contribution decreases with increase of Reynolds number.
基金Supported by the National Natural Science Foundation of China (Grant Nos.10572022,10772022)
文摘Large-scale amplitude liquid sloshing in container under pitching excitation is numerically studied in this paper.Firstly,the kinematics of the ALE description is introduced and the fluid dynamics equations are revised in the ALE form.Secondly,the boundary condition about free-surface tension is represented in the form of weak integration that can be computed by the differential geometry method derived in the present paper and the normal vector on free surface is calculated using accurate formulas presented in this paper.Then the numerical discretized equations of fractional step finite element method are developed by Galerkin weighted residual method.Furthermore,the numerical simulation of large-scale amplitude sloshing of the liquid both in rectangular container and cylindrical container is carried out.The computed time evolution of the wave height,and free surface profiles at different time are obtained.Comparisons among the present numerical results with other published numerical results and experimental data confirm the effectiveness and validity of the method developed in this paper.
基金Project supported by the Scientific Research Foundation of Anhui (Grant No. 00021090)the Natural Science Foundation of Jiansu Higher Education(Grant No.02KJD13004).
文摘The dynamic characteristics of liquid sloshing in a transversely vibrating spherical tank with spacer under low gravity were investigated. By expanding the characteristic functions, the frequencies and velocity potentials of liquid free-sloshing were obtained. The dynamic equations and boundary conditions of liquid sloshing in the traverse vibrational spherical tank with spacer under low gravity were derived. By modifying the velocity potentials of liquid free-sloshing, the velocity potentials of liquid sloshing in the traverse vibrating spherical tank with a spacer were obtained. Furthermore, the forces and the moments acting on tank wall were given. The numerical results show when a spacer is inserted in the tank, the sloshing frequencies of liquid and the forces acting on tank wall will decrease, but the moment of force to the centre of the tank which is caused by the force of liquid acting on the spacer will occur.
文摘In this paper, the couple vibration of liquid and elastic spacer in arectangular tank is investigated. Two different velocity potential functions correspondingrespectively to the liquid above and below the elastic spacer are assumed. Complicated boundaryconditions corresponding to two velocity potential functions and vibrations of elastic spacer aregiven. Using the method of energy, the equation of couple frequency is obtained. Through numericalcomputation the natural frequencies that change according to the location and stiffness of thespacer are shown.
基金Supported by the Open Research Fund of State Key Laboratory of Transient Optics and Photonics of Chinese Academy of Sciences under Grant No SKLST201508the China Postdoctoral Science Foundation Funded Project under Grant No 2015M580945the Government of Chaoyang District Postdoctoral Research Foundation
文摘The angle compensation method is adopted to detect sloshing waves by laser diffraction, in the case that the wavelength of the sloshing waves is much greater than that of the incident light. The clear diffraction pattern is observed to be of asymmetry, involving orders, position and interval of the diffraction spots that are discovered during the light grazing incidence. It is found that the larger the angle of incidence is, the more obvious the asymmetry is. The higher the negative diffraction orders are, the smaller the intervals between spots are. On the contrary~ in the positive region, the higher the diffraction orders are, the larger the spot intervals are. The positive interval is larger than that of the same negative diffraction order. If the incident angle reaches 1.558 rad in the experiment, all positive diffraction orders completely vanish. Based on the mechanism of phase modulation and with the Fourier transform method, the relations between the incident angle and position, interval spaces, and orders of diffraction spots are derived theoretically. The theoretical calculations are compared with the experimental data, and the comparison shows that the theoretical calculations are in good agreement with the experimental measurement.
文摘The mathematical formulation of sloshing dynamics for a partially liquid filleddewar container driven by the gravity jitter acceleration associated with slew motion isstudied.Explicit mathematical expressions to manage jitter accelerption associated withslew motion which is acting on the fluid systems in microgravity are derived. Thenumerical computation of sloshing dymamics is based on the non-inertia framecontainer bound coordinate and the solution of time-dependent three-dimensionalformulations of partial differential equations subject to initial and boundary conditions.The numerical computation of fluid viscous stress forces and moment fluctuationsexerted on the dewar container driven by jitter acceleration associated with slew motion is investigated.
文摘The dynamical behavior of fluids affected by the asymmetric gravity jitter oscillations, in particular, the effect of surface tension on partially-filled rotating fluids in a Dewar tank imposed by time-dependent directions of background reduced gravity accelerations is investigated. Results show that the greater the components of background reduced gravity in radial and circumferential directions, the greater will be the tendency toward increasing amplitude and degrees of asymmetry of the liquid-vapor interface profiles.
基金supported by the National Natural Science Foundation of China (No. 10632040)the Tianjin Natural Science Foundation (No. 09JCZDJC26800)
文摘The nonlinear equations of an elastic tank-liquid coupling system subjected to the external excitation are established.By means of the multi-scale method and the singularity theory,the bifurcation behaviors of the system are investigated and analyzed.The various nonlinear dynamical behaviors of the coupling system are obtained,which can further explain the relationship between the physical parameters and the bifurcation solutions.The results provide a theoretical basis to the realization of the parameter optimal control.